it is noted that terms like “ preferably ”, “ commonly ”, and “ typically ” are not utilized herein to limit the scope of the claimed invention or to imply that certain features are critical , essential , or even important to the structure or function of the claimed invention . rather , these terms are merely intended to highlight alternative or additional features that may or may not be utilized in a particular embodiment of the present invention . for the purposes of describing and defining the present invention , it is noted that the term “ substantially ” is utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison , value , measurement , or other representation . the term “ substantially ” is also utilized herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue . as used herein , the term “ analyte ” refers to a substance , or group of substances , whose presence or amount thereof is to be determined . as used herein , the term analyte subsumes the term “ antigen ”, which refers to any compound that can bind to an antibody . the term “ antibody ” means a specific binding partner of the analyte and is any substance , or group of substances , which has a specific binding affinity for the analyte to the essential exclusion of other unrelated substances . the term includes polyclonal antibodies , monoclonal antibodies , and antibody fragments . the term “ hapten ” refers to a partial or incomplete antigen . haptens are protein - free substances , mostly low molecular weight substances , which are not capable of stimulating antibody formation , but which do react with antibodies . the latter are formed by coupling a hapten to a high molecular weight carrier and injecting this coupled product into humans or animals . examples of haptens include 6 - monoacetylmorphine and 6 - monoacetylcodeine . the term “ activated hapten ” refers to a hapten that has been provided with an available reaction site , for example , by the attachment of a linking group carrying a reactive moiety , that can be used to connect the hapten to a carrier , immunogen , label , tracer , or other moiety . the term “ linker ” refers to a chemical moiety that connects a hapten to a carrier , immunogen , label , tracer , or another linker . linkers may be straight or branched , saturated or unsaturated carbon chains . they may also include one or more heteroatoms within the chain or at termini of the chains . by heteroatoms is meant atoms other than carbon which are chosen from the group consisting of oxygen , nitrogen , and sulfur . the use of a linker may or may not be advantageous or needed , depending on the specific hapten and carrier pairs . a “ carrier ”, as the term is used herein , is an immunogenic substance , commonly a protein , which can join with a hapten , thereby enabling the hapten to stimulate an immune response , or a substance that can form a conjugate useful in immunoassay , e . g ., aminodextran and bovine serum albumin ( bsa ). carrier substances include proteins , glycoproteins , complex polysaccharides , and nucleic acids that are recognized as foreign and thereby elicit an immunologic response from the host . poly ( amino acids ) useful as carriers include keyhole limpet hemocyanin , bovine thyroglobulin , and bovine serum albumin . the terms “ immunogen ” and “ immunogenic ” as used herein refer to substances capable of producing or generating an immune response in an organism . the term “ derivative ” refers to a chemical compound or molecule made from a parent compound by one or more chemical reactions . the term “ conjugate ” refers to any substance formed from the joining together of two parts . representative conjugates in accordance with the present invention include those formed by the joining together of a small molecule and a large molecule , such as a protein . the term conjugate subsumes the term immunogen . as used herein , a detector molecule , label , or tracer is an identifying tag which , when attached to a carrier substance or molecule , can be used to detect an analyte . a label may be attached to its carrier substance directly or indirectly by means of a linking or bridging moiety . examples of labels include enzymes such as β - galactosidase and peroxidase , fluorescent compounds such as rhodamine and fluorescein isothiocyanate ( fitc ), luminescent compounds such as dioxetanes and luciferin , and radioactive isotopes such as 125 i . the term active ester within the sense of the present invention encompasses activated ester groups which can react with nucleophiles such as , but not limited to , free amino groups of peptides , polyaminoacids , polysaccharides , or labels under such conditions that no interfering side reactions with other reactive groups of the nucleophile - carrying substance can occur . an object of the present invention is to provide a compound having the structure : where r is a saturated or unsaturated , substituted or unsubstituted , straight or branched chain of 0 - 10 carbon or hetero atoms , l is a linker group consisting of 0 - 2 substituted or unsubstituted aromatic rings , and y is an activated ester or nh - z where z is a carrier or label and x is nh or o . another object of the present invention is to provide a compound having the structure : where r is ch 2 or c ═ o , l is a saturated or unsaturated , substituted or unsubstituted , straight or branched chain of 0 - 10 carbon or hetero atoms , and y is an activated ester or nh - z where z is a carrier or label and x is nh or o . yet another object of the present invention is to provide a compound having the structure : a further object of the present invention is to provide antibodies which have specificity for 6 - monoacetylmorphine and which are produced in response to a compound having the structure : where r is a saturated or unsaturated , substituted or unsubstituted , straight or branched chain of 0 - 10 carbon or hetero atoms , l is a linker group consisting of 0 - 2 substituted or unsubstituted aromatic rings , x is nh or o , and y is nh - z where z is a carrier . a further object of the present invention is to provide antibodies which have specificity for 6 - monoacetylcodeine and which can be produced in response to a compound having the structure : yet a further object of the present invention is to provide antibodies which have specificity for 6 - monoacetylmorphine and 6 - monoacetylcodeine and which can be produced in response to a compound having the structure : where r is ch 2 or c ═ o , l is saturated or unsaturated , substituted or unsubstituted , straight or branched chain of 0 - 10 carbon or hetero atoms , x is nh or o , and y is nh - z where z is a carrier . the synthetic schemes for immunogens and screening conjugates of monoacetyl morphine and monoacetylcodeine are illustrated in fig1 through fig7 . codeine is reduced to dihydrocodeine ( see fig1 ) using hydrogen gas , preferably palladium on charcoal as catalyst under pressure . hydrogenation reactions are well known in the art and can be performed using many different catalysts such as raney ni , palladium hydroxide on charcoal , adam &# 39 ; s catalyst , etc in solvents such as methanol , ethanol , or ethyl acetate . the secondary hydroxyl group of dihydrocodeine is oxidized back to carbonyl group . many literature references are known for conversion of a secondary hydroxyl group to carbonyl functionality , e . g ., oxalyl chloride / dmso , pyridinium chlorochromate and chromium oxide / pyridine , most preferably benzophenone and potassium t - butoxide under reflux conditions to give compound 3 . the latter intermediate then undergoes reductive amination to give aminodihydrocodeine ( 4 ) in the presence of ammonium acetate and a reducing agent , sodium cyanoborohydride , preferably at a ph of 6 to 7 , thus providing a mixture of two diastereomers ( compound 4 ). acetylation reaction of the amino group of compound 4 can be performed using acetic anhydride and pyridine at a temperature ranging from room temperature to reflux conditions . this reaction is performed using acetic anhydride as the acetylating agent and a base using triethylamine in the presence of 4 - dimethylaminopyridine . the acetylated product is obtained as a mixture of diastereomers and can be separated by either column chromatography or preparative hplc . chromatographic techniques to separate diastereomers are well known in the art . the desired isomer ( compound 5b ) is demethylated to give the phenolic compound 6 ( fig2 ). a variety of demethylation reactions are known in the art , for example , trimethylsilyl iodide , sodium thioethoxide , potassium thiophenoxide , sodium cyanide in dmso , aluminium tribromide in ethane thiol , aluminium chloride / dimethyl sulfide , and hydrobromic acid boron tribromide ( greene , t . and wuts , p ., “ protective groups in organic synthesis ”, 2 nd edition , wiley intersciences , 1991 ) at a temperature ranging from 0 ° to room temperature . preferably the demethylation of the compound 5b is done in the presence of boron tribromide in dichloromethane at room temperature . the phenolic hydroxyl group of compound 5b is then extended with a protected carboxyl terminated linker through an ether linkage ( fig2 ). the phenolic hydroxyl group can also be converted to a carboxyl leashed linker by an ester or urethane linkage . the t - butylester group of compound 7 is deprotected to a carboxylic acid functionality followed by conversion to an n - hydroxysuccinimide ester ( compound 9 ). the activation of a carboxyl group can be accomplished by an activation step using a carbodiimide such as dicyclohexylcarbodiimide , 1 -[ 3 -( dimethylamino ) propyl ]- 3 - ethylcarbodiimide hydrochloride ( edc ), or n , n , n ′, n ′- o - succinimidyl - tetramethyluronium tetrafluoroborate . conjugation to a protein provides an immunogen ( compound 10 ) and screening conjugates . the extension of the phenolic group can also be done using an alkylating reagent or acylating reagent with protected amino group ( fig3 ). an example of an amino protecting group is a phthalimido group , which can be cleaved under methyl amine or hydrazine . the amino group of the resultant amino leashed product is amenable to acylation reactions with a wide variety of carboxyl activated linker extensions or labels that are well known to those skilled in the art . linker extension is often performed to generate a terminal activating group . linker extension using a homobifunctional linker such as n - hydroxysuccinimide ester of a biscarboxylic acid such as terephthalic acid or 4 , 4 - biphenyl dicarboxylic acid ( fig3 ) can be used to generate an activated ester ( compound 15 ) in a single step by reaction with the aforementioned amino group ( compound 14 ). for a good treatise on the subject of linkers , the reader is referred to hermanson , greg t ., “ bioconjugate techniques ”, academic press inc ., 1996 . the 6 - hydroxyl group of compound 15 is acetylated . acetylation reaction can be done preferably using pyridine and acetic anhydride . the resulting active ester is conjugated to protein for use as a screening conjugate . the immunogen leashed out of the nitrogen can use dihydronormorphine ( compound 18 ) as a starting material . protection of amino group in the presence of free phenolic hydroxyl group is known in the art . these reactions can be done by a proper choice of protecting group and reaction conditions . an example of an n - protecting group removed under mild basic conditions is fluoromethyloxycarbonyl ( fmoc ). an example of an n - protecting group easily removed with acid is t - butoxycarbonyl ( boc ). an example of an n - protecting group removed under neutral hydrogenation conditions is a carbobenzyloxy group ( cbz group ). in this embodiment , the preferred protection of the cyclic secondary amine of dihydronormorphine is use of a carbobenzyloxy group in this sequence ( fig4 ). the phenolic group of cbz protected derivative ( compound 19 ) can be protected as a benzyl group . the secondary hydroxyl group is then converted to an acetyl group ( compound 21 ). one of the preferred acetylation reactions of the hydroxyl group is use of pyridine and acetic anhydride under reflux conditions . deprotection of n - cbz and benzyl groups can be achieved in one step using hydrogen and palladium on a charcoal catalyst to give compound 22 . the free secondary amine is extended to a carboxyl group though a succinylation reaction or a reductive amination reaction with succinic semialdehyde and sodium cyanoborohydride at a ph of 6 - 7 . the compound 22 is then converted to an active ester ( compound 23 ). the activation of a carboxyl group is accomplished by an activation step using a carbodiimide such as dicyclohexylcarbodiimide ( dcc ), edc , or n , n , n ′, n ′- o - succinimidyl - tetramethyluronium tetrafluoroborate . conjugation to protein provides immunogen and screening conjugates . in a different embodiment , n - leashed 6 - acetamido 6 - mam protein conjugate ( fig5 and fig6 ) can also be made . the phenolic hydroxyl group of compound 6 can be protected as a benzyl group n - demethylation of cyclic secondary amine is well known in the literature and can be achieved under various reaction conditions , such as 1 - chloroethyl chloroformate followed by methanol , cyanogens bromide followed by zn dust , or with vinyl chloroformate followed by treatment with hydrobromic acid . the preferred reaction used for n - demethylation of compound 26 is treatment of 1 - chloroethyl chloroformate followed by methanol to give compound 28 ( fig5 ). deprotection of the benzyl group is done under hydrogenation conditions using 10 % palladium hydroxide on charcoal . extension at the nitrogen position to a carboxyl terminal group by reductive amination ( fig5 ) followed by a carboxyl group activation procedure can be done as described earlier . extension at the nor position to a carboxy terminal group can also be achieved by succinylation of compound 28 to compound 33 ( fig6 ). deprotection of the benzyl group followed by activation of the carboxylic group functionality can be achieved as described earlier . fig7 describes the preparation of a monoacetylcodeine immunogen . this can be used as a booster antibody for preparation of a 6 - mam antibody cross - reactive with 6 - monoacetyl codeine . during the n - demethylation of compound 5b using 1 - chloroethyl chloroformate in 1 , 2 - dichloroethane , compound 38 was formed in one step . it was anticipated that the intermediate n -( 1 - chloroethoxy ) carbonyl derivative ( 37 ) underwent hydrolysis under the reaction conditions to give compound 38 . extension at the nor position to a carboxy terminal functionality has been discussed earlier . activation is followed by conjugation to a protein for preparation of the immunogen ( compound 41 ). in order that the invention may be more readily understood , reference is made to the following examples , which are intended to illustrate the invention but not limit the scope thereof . in the examples that follow , boldface numbers refer to the corresponding structure in the drawings . to 1 . 2 g ( 4 . 0 mmol ) of codeine in 40 ml of methanol was added 100 mg of 10 % pd — c . the resulting reaction mixture was hydrogenated under pressure of 50 psi . the solution was filtered through celite ( celite corporation ), and the filtrate was concentrated to give 1 . 12 g ( 3 . 7 mmol , 93 %) of dihydrocodeinone as a white solid . es (+) m / z 301 . to a mixture of 1 . 25 g ( 11 . 1 mmol ) of potassium - t - butoxide in 50 ml of benzene were added 6 . 78 g ( 37 mmol ) of benzophenone and 1 . 12 g ( 3 . 7 mmol ) of dihydrocodeine , which was allowed to reflux for 2 hours . the reaction mixture turned yellow . the reaction mixture was allowed to cool to room temperature , and 50 ml of 2n hcl was added . the resulting reaction mixture was allowed to stir for 10 minutes . the organic layer was separated and extracted with 3 × 40 ml of 2n hcl . the organic layer was discarded , and the aqueous layer was again extracted with 3 × 20 ml of dichloromethane . the aqueous layer was basified with aqueous potassium hydroxide solution to ph 12 and extracted with 5 × 60 ml of dichloromethane . the organic layers were combined and dried over mgso 4 and filtered . the filtrate was concentrated to give 691 mg ( 2 . 3 mmol , 55 %) of 3 as a yellow solid . to 3 . 46 g ( 11 . 5 mmol ) of compound 3 in 70 ml of methanol was added 8 . 92 g ( 115 mmol ) of ammonium acetate , which was and allowed to stir at room temperature for 15 minutes , at which time a clear solution was obtained . to the reaction mixture a solution of 727 mg ( 11 . 5 mmol ) of sodium cyanoborohydride was added , and the ph of the reaction mixture was adjusted to ph 6 - 7 by addition of conc . hcl . the reaction mixture was allowed to stir at room temperature for 18 hours and concentrated under reduced pressure to give yellow oil . to this yellow oil 250 ml of water was added , and the ph was adjusted again to 1 with 6n hcl . the resulting aqueous reaction mixture was extracted with 2 × 250 ml of dichloromethane . the ph of the aqueous part was readjusted to 1 using 6n hcl and extracted with 3 × 250 ml of dichloromethane . the organic layers were combined , dried ( mgso 4 ), and concentrated to give 3 . 2 g ( 10 . 6 mmol , 92 %) of 4 as a thick yellow oil . this product was used in the next step without purification . hr - es (+): calculated for c 18 h 24 n 2 o 2 , m + h 301 . 1911 ; observed 301 . 1913 . to 3 . 2 g ( 10 . 6 mmol ) of amino dihydrocodeine 4 in 125 ml of dichloromethane were added 87 mg ( 0 . 71 mmol ) of 4 - dimethylaminopyridine and 9 ml of triethylamine . the reaction mixture was allowed to cool to 0 ° c ., and 7 . 1 ml ( 74 mmol ) of acetic anhydride was added . the reaction mixture was allowed to warm up to room temperature and allowed to stir for 18 h . the reaction mixture was concentrated under reduced pressure , and a yellow oil was obtained . to this yellow oil 125 ml of water was added , and the product was extracted with 4 × 150 ml of dichloromethane . the ph of the aqueous solution was adjusted to 10 , and the solution was re - extracted with chloroform . all the organic layers were combined , dried ( mgso 4 ), and concentrated to give a colorless crude oil . lc - ms analysis indicated formation of two diastereomers . one half of the crude product was purified by rp - hplc ( c - 18 column ) using a gradient run with acetonitrile - water containing 0 . 1 % trifluoroacetic acid . fractions containing the desired isomer were combined and concentrated , followed by lyophilization to give 614 mg of product 5b as an off - white power . hr - es (+) calculated for c 20 h 26 n 2 o 3 , m + h 343 . 2016 ; observed 343 . 2022 . to 644 mg ( 1 . 8 mmol ) of dihydrocodeine derivative ( 5b ) was added 12 ml dichloromethane . this solution was added to a magnetically stirred solution of 11 . 3 ml ( 11 . 2 mmol ) of 1m bbr in 20 ml of dichloromethane at room temperature . the reaction mixture was allowed to stir at room temperature for 1 h and was poured in 60 ml of conc . nh 4 oh solution and 30 g of ice . the reaction mixture was allowed to stir for 1 h and extracted with 5 × 100 ml of 80 % ethanol in dichloromethane . the organic layers were combined , dried , and concentrated . the residue was purified by preparative rp - hplc using using a gradient run with acetonitrile - water containing 0 . 1 % trifluoroacetic acid . fractions containing the desired product were combined and concentrated followed by lyophilization to give 480 mg ( 78 %, 1 . 46 mmol ) of 6 as an off - while solid . lr - es (+) m + h 329 . to 50 mg ( 0 . 15 mmol ) of acetamido dihydromorphine derivative ( 6 ) was added 6 ml of anhydrous acetone , 0 . 5 ml of anyhdrous dimethylformamide , 150 mg ( 1 . 08 mmol ) of potassium carbonate , and 140 μl ( 0 . 78 mmol ) of t - butylbromobutyrate . the reaction mixture was allowed to reflux under argon atmosphere for 18 h , cooled to room temperature and filtered . the filtrate was concentrated under reduced pressure , redissolved in 60 ml of chloroform , and 25 ml of water was added . the organic part was separated , and the aqueous part was extracted with 3 × 50 ml of chloroform . all organic layers were combined , dried ( mgso 4 ), and concentrated . the residue was purified by silica gel flash column chromatography using 10 % methanol in chloroform to give 35 mg ( 48 %, 0 . 074 mmol ) of 7 as a thick colorless oil . lr - ms - es (+): m + h 471 . to 35 mg ( 0 . 074 mmol ) of acetamido dihydromorphine butyric acid derivative ( 7 ) was added 3 ml of dichloromethane and 1 ml of trifluoroacetic acid . the reaction mixture was allowed to stir at room temperature for 30 minutes and concentrated . to the residue 10 ml of dichloromethane was added and concentrated . the residue was purified by preparative rp - hplc using a gradient run with acetonitrile - water containing 0 . 1 % trifluoroacetic acid . fractions containing the desired product were combined and concentrated followed by lyophilization to give 19 mg ( 0 . 045 mmol , 63 %) of desired product 8 as white powder . hr - es (+): calculated for c 23 h 30 n 2 o 5 ; m + h 415 . 2228 ; observed 415 . 2227 . to 17 mg ( 0 . 041 mmol ) of acetamido dihydromorphine butyric acid ( 8 ) was added 3 ml of freshly distilled thf and the mixture was cooled to 0 ° c . to the reaction mixture was added 21 . 4 μl ( 0 . 12 mmol ) of n , n - diisopropylethylamine followed by 37 mg ( 0 . 12 mmol ) of o -( n - succinimidyl )- n , n , n ′, n ′- tetramethyluronium tetrafluoroborate . the reaction mixture was allowed to warm up to room temperature and allowed to stir at room temperature 18 h . the reaction mixture was concentrated and the residue was purified by preparative rp - hplc using a gradient run with acetonitrile - water containing 0 . 1 % trifluoroacetic acid . fractions containing the desired product were combined and concentrated followed by lyophilization to give 13 mg ( 0 . 02 mmol , 62 %) of 9 as white solid . lr - ms - es (+): m + h 512 . a solution of 37 mg of keyhole limpet hemocyanin ( klh ) in 1 . 2 ml of 50 mm potassium phosphate ( ph 7 . 5 ) was cooled in an ice bath . to the reaction mixture 1 . 5 ml of dmso was added dropwise , and the reaction temperature was maintained below room temperature . then a solution of 8 mg ( 0 . 015 mmol ) of 9 in 1 ml of dmf was added to the protein solution dropwise . the mixture was allowed to warm up to room temperature and was allowed to stir at room temperature 18 h . the resulting conjugate was placed in a dialysis tube ( 10 , 000 mw cut - off ) and was dialyzed in 1 l of 70 % dmso in 50 mm potassium phosphate ( ph 7 . 5 , at least 3 hour ), 1 l of 50 % dmso in 50 mm potassium phosphate ( at least 3 hours ), 1 l of 30 % dmso in 50 mm potassium phosphate ( at least 3 h ), 1 l of 10 % dmso in 50 mm potassium phosphate ( at least 3 h ) at room temperature followed by 50 mm potassium phosphate buffer ( 6 times , at least 6 h each at 4 ° c .). the protein concentration was determined to be 2 . 2 mg / ml using biorad coomassie blue protein assay ( bradford , m ., anal . biochem . 72 , 248 , 1976 ). the extent of available lysine modifications was determined to be 46 % by the tnbs method ( habeeb afsa , anal biochem . 14 , 328 - 34 , 1988 ). a mixture of 10 . 0 g ( 0 . 041 mol ) of 4 , 4 ′- biphenyldicarboxylic acid in 200 ml of anhydrous thf ( distilled over na and benzophenone ) under argon was treated with 25 . 0 ml ( 0 . 286 mol ) of oxalyl chloride followed by 0 . 1 ml of anhydrous dmf . the reaction was then concentrated at reduced pressure to a yellow oil . this was stripped down 5 times with anhydrous thf to drive off any residual oxalyl chloride to yield 11 . 5 g of the desired product 11 as a yellow solid . this was used in the next step without purification . ms : m / e 278 ( m ). a solution of 11 . 5 g ( 0 . 041 mol ) of 11 in 500 ml of anhydrous dichloromethane under argon was treated with 25 . 0 g ( 0 . 217 mol ) of n - hydroxysuccinimide followed by 25 ml of triethylamine and stirred at room temperature overnight . the resulting precipitate was collected by suction filtration and washed with dichloromethane to yield 10 . 7 g of product as a white solid . the filtrate was concentrated at reduced pressure , and the residue was triturated with dichloromethane to yield 3 . 84 g of a second crop as a white solid for a combined yield of 14 . 5 g ( 81 %) of the desired product 12 . ms m / e 437 ( m + h ). 1 . 5 g ( 37 . 5 mmol ) of nah ( 60 % dispersion in mineral oil ) was rinsed with 2 × 25 ml of hexanes to remove the oil . to the reaction mixture was added 140 ml of anhydrous dmf followed by 10 . 1 g ( 35 mmol ) of morphine . this mixture was allowed to stir at room temperature for 30 minutes under nitrogen atmosphere , and 14 . 5 g ( 53 mmol ) of n -( 3 - bromopropyl ) phthalimide was added . the reaction mixture was allowed to stir 18 h at room temperature . the reaction was monitored by thin layer chromatography ( silica , 7 : 2 : 1 : 1 , meoh : etac : nh 4 oh : h 2 o , l 2 visualization ), which showed that the reaction was incomplete . to the reaction mixture 0 . 15 g ( 3 . 75 mmol ) of nah ( 60 % in oil ) was added , and the mixture was allowed to stir for an additional 1 . 5 h . the mixture was poured into 350 ml of ice - water and extracted with 250 ml of ethyl acetate . the organic layer was separated , and the aqueous layer was extracted with 2 × 250 ml of ethyl acetate . the organic layers were combined and washed with 2 × 150 ml of water , 150 ml of 1n naoh and 2 × 150 ml of water . the organic layer was dried ( na 2 so 4 ) and concentrated . the residue was crystallized with diethyl ether to give 12 . 9 g ( 27 . 3 mmol , 77 %) of the desired product 13 as a white solid . to 14 g ( 29 . 6 mmol ) of 3o - phthalimidopropyl morphine ( 13 ) was added 188 ml of 2m ethanolic methylamine , and the reaction mixture was allowed to stir for 3 . 5 h at room temperature under nitrogen . the reaction mixture was poured into 650 ml of chloroform and 425 ml of cold water . the organic layer was separated , and the aqueous layer was extracted with 3 × 90 ml of chloroform . the chloroform layers were combined and extracted with 2 × 140 ml of 1n hcl . the aqueous extract was basified with 140 ml of 2 . 5 n naoh and extracted with 3 × 300 ml of chloroform . the organic layer was dried ( na 2 so 4 ) and concentrated . the residue was crystallized from diethyl ether to give 8 . 9 g ( 26 mmol , 88 %) of 14 as a white solid . to a mixture of 6 . 4 g ( 14 . 6 mmol ) of biphenyl di - n - hydroxysuccinimide ester ( 12 ) in 400 ml of anhydrous thf was added a solution of 3 . 2 g ( 9 . 3 mmol ) of 3o - aminopropylmorphine ( 14 ) in 400 ml of anhydrous thf dropwise over a period of 30 minutes . the reaction mixture was allowed to stir at room temperature for 2 h and filtered . the filtrate was concentrated , and the residue was dissolved in 250 ml of dichloromethane . this was washed with 150 ml of saturated aqueous sodium bicarbonate solution dried ( na 2 so 4 ), and concentrated . the residue was purified by silica gel column chromatography , first by eluting with ethyl acetate to remove the higher rf impurities followed by eluting with anhydrous thf to give the desired product as a free base . all the fractions containing the desired product ( rf0 . 13 ) were combined and treated with 12 ml of 1m hcl in ether . the solution was then concentrated at reduced pressure to give 3 . 2 g ( 49 %, 4 . 5 mmol ) of 15 as a white solid . ms : m / e 664 ( m + h ). to 50 mg ( 0 . 071 mmol ) of morphine 3 - o - aminopropylbiphenyl n - hydroxysuccinimide ester hydrochloride salt 15 was added 1 ml of anhydrous dmf , 7 . 1 μl of acetic anhydride , and 6 . 1 μl of anhydrous pyridine . the reaction mixture was allowed to stir 18 h . an analytical hplc was run using rp - hplc column ( c - 18 ) using acetonitrile and water containing 0 . 1 % trifluoroacetic acid to monitor the progress of the reaction . the result indicated the presence of only starting material . to the reaction mixture 14 μl of acetic anhydride and 12 μl of pyridine were added . the mixture was allowed to stir for 6 h , and hplc analysis indicated no reaction . to the reaction mixture 20 μl of acetic anhydride was added and allowed to stir 18 h . to the reaction mixture 0 . 5 ml of pyridine and 40 μl of acetic anhydride were added . the reaction mixture was allowed to stir at room temperature 18 h , and hplc analysis indicated product formation . this was concentrated under reduced pressure to give a yellow oil and was purified by rp - hplc ( c - 18 column ) using a gradient run with acetonitrile - water containing 0 . 1 % trifluoroacetic acid . fractions containing the desired isomer were combined and concentrated followed by lyophilization to give 32 mg ( 64 %, 0 . 04 mmol ) of desired product 16 as white solid . hr - es (+): calculated for c40h39n3o9 , m + h 706 . 2759 ; observed 706 . 2758 . to 500 mg of bovine serum albumin ( bsa ) was added 6 ml of 50 mm potassium phosphate , and the solution was allowed to cool to 0 ° c . to the reaction mixture 6 ml of dmso were added dropwise for a period of 5 minutes . a solution of 13 mg ( 0 . 018 mmol ) 6 - mam nhs ester derivative ( 16 ) in 1 ml of anhydrous dmf was added to the reaction mixture dropwise at 0 ° c . the mixture was allowed to warm up to room temperature and was allowed to stir at room temperature 18 h . the resulting conjugate was placed in a dialysis tube ( 10 , 000 mw cut - off ) and was dialyzed in 1 l of 70 % dmso in 50 mm potassium phosphate ( ph 7 . 5 , 3 hours ), 1 l of 50 % dmso in 50 mm potassium phosphate ( at least 3 hours ), 1 l of 30 % dmso in 50 mm potassium phosphate ( at least 3 h ), 1 l of 10 % dmso in 50 mm potassium phosphate ( at least 3 h ) at room temperature followed by 50 mm potassium phosphate buffer ( 6 times , at least 6 h each at 4 ° c .). the protein concentration was determined to be 15 mg / ml using biorad coomassie blue protein assay . the extent of available lysine modification was determined to be 46 % by the tnbs method . to 200 mg ( 0 . 73 mmol ) of dihydro normorphine ( 18 ) is added 12 ml of thf and 8 ml of water . to the reaction mixture 310 mg ( 2 . 92 mmol ) of sodium carbonate is added followed by 0 . 12 ml ( 0 . 84 mmol ) of benzylchloroformate . the mixture is allowed to stir at room temperature 18 h and concentrated under reduced pressure . to the residue 10 ml of water is added , and the ph is adjusted to 2 using 3n hcl . this is extracted with ethyl acetate , dried , and concentrated . the residue is purified by silica gel column chromatography to give 19 . to 100 mg ( 0 . 23 mmol ) of compound 19 in 5 ml of anhydrous dmf is added 33 μl ( 0 . 27 mmol ) of benzyl bromide , 55 mg ( 0 . 39 mmol ) of potassium carbonate , and the reaction mixture is heated at 60 ° c . for 6 h , filtered , and the filtrate is concentrated . the residue is purified by silica gel column chromatography to give 20 . to 100 mg ( 0 . 20 mmol ) of 20 is added 1 . 5 ml of pyridine and 74 μl ( 0 . 78 mmol ) of acetic anhydride . the reaction mixture is allowed to stir and is heated at 90 ° c . for 3 h . the resulting reaction mixture is allowed to cool to room temperature and concentrated . the residue is purified by silica gel column chromatography to give 21 . to 100 mg ( 0 . 18 mmol ) of compound 21 is added 30 ml of ethanol and 50 mg of 20 % pd ( oh ) 2 / c . the reaction mixture is hydrogenated at 60 psi for 6 h . the reaction mixture is filtered through celite , and the filtrate is concentrated to give compound 22 . to 100 mg ( 0 . 31 mmol ) of 6 - acetyl dihydronormorphine ( 22 ) is added 25 ml of freshly distilled thf . the reaction mixture is allowed to stir at room temperature 266 μl ( 0 . 38 mmol ) of succinic semialdehyde ( 15 wt % solution in water ) is added followed by 24 mg ( 0 . 38 mmol ) of sodium cyanoborohydride . the ph of the reaction mixture is adjusted between 6 - 6 . 5 , and the reaction mixture is allowed to stir at room temperature for 6 h . the reaction mixture is concentrated under reduced pressure , and 50 ml of dichloromethane is added followed by 25 ml of water . the organic layer is separated , and the aqueous layer is extracted with 2 × 50 ml of dichloromethane . the combined organic layers are dried and concentrated . the residue is purified by silica gel column chromatography to give 23 . to 100 mg ( 0 . 24 mmol ) of 6 - acetyl dihydronormorphine n - butyric acid ( 23 ) is added 30 ml of freshly distilled thf , and the mixture is cooled to 0 ° c . to the reaction mixture is added 0 . 10 ml ( 0 . 57 mmol ) of n , n - diisopropylethylamine followed by 171 mg ( 0 . 57 mmol ) of o -( n - succinimidyl )- n , n , n ′, n ′- tetramethyluronium tetrafluoroborate . the reaction mixture is allowed to warm up to room temperature and is allowed to stir at room temperature 18 h . the reaction mixture is concentrated , and the residue is purified silica gel column chromatography to give 24 . this conjugate is prepared from compound 24 according to the procedure described for the conversion of compound 9 to compound 10 . to 500 mg ( 1 . 52 mmol ) of 6 is added 12 ml of anhydrous dmf followed by 270 μl ( 2 . 26 mmol ) of benzyl bromide and 734 mg ( 5 . 3 mmol ) of anhydrous potassium carbonate . the reaction mixture is allowed to heat at 60 ° c . for 18 h , then is cooled to room temperature and filtered . the filtrate is concentrated and purified by preparative rp - hplc using using a gradient run with acetonitrile - water containing 0 . 1 % trifluoroacetic acid . fractions containing the desired product are combined and concentrated followed by lyophilization to give 26 . to 250 mg ( 0 . 59 mmol ) of 26 is added 5 ml of 1 , 2 - dichloroethane . the resulting solution is allowed to stir , and 636 μl ( 5 . 8 mmol ) of 1 - chloroethyl chloroformate is added . the reaction mixture is heated under reflux conditions 18 h , and an additional 640 μl ( 5 . 9 mmol ) of 1 - chloroethyl chloroformate is added . the reaction is heated to reflux for 18 h and concentrated . the residue is used in the next step without purification . to all of the above [ 6 - acetamido - 3 - o - benzyl n -[ 1 - chloroethoxy carbonyl ] nordihydromorphine ( 27 ) is added 5 ml of methanol and the mixture is allowed to heat to reflux for 6 h . the reaction mixture is concentrated , and the residue is purified by preparative rp - hplc using a gradient run with acetonitrile - water containing 0 . 1 % trifluoroacetic acid . fractions containing the desired product are combined and concentrated followed by lyophilization to give 28 . to a solution of 100 mg ( 0 . 24 mmol ) of 28 in ethanol is added 10 % pd — c , and the mixture is allowed to hydrogenate under 60 psi for 12 h . the reaction mixture is filtered , and the filtrate is concentrated to give 29 . compound 30 is prepared from compound 29 following the procedure as described for the preparation of compound 23 . this active ester is prepared from compound 30 according to the procedure used to convert the acid 23 to active ester 24 . this conjugate is prepared according to the procedure described for conjugate 10 . to 250 mg ( 0 . 73 mmol ) of 5b was added 5 ml of 1 , 2 - dichloroethane . the resulting solution was allowed to stir , and 636 μl ( 5 . 8 mmol ) of 1 - chloroethyl chloroformate was added . the reaction mixture was allowed to heat to reflux 18 h , and an additional 640 μl ( 5 . 9 mmol ) of 1 - chloroethyl chloroformate was added . the reaction mixture was heated under reflux conditions for an additional 18 h and concentrated . the residue was purified by preparative rp - hplc using a gradient run with acetonitrile - water containing 0 . 1 % trifluoroacetic acid . fractions containing the desired product were combined and concentrated followed by lyophilization to give 75 mg ( 0 . 22 mmol , 31 %) of 38 ( m + h 329 ) as a white solid . [ note : the intermediate 6 - acetamido - n -( 1 - chloroethoxy ) nordihydrocodeine ] derivative ( 37 ) was anticipated to be formed under reaction conditions and was hydrolyzed under reaction conditions ]. this compound 39 is prepared from compound 38 , following the procedure as described for the preparation of compound 23 . this active ester is prepared from compound 39 according to the procedure used to convert the acid 23 to active ester 24 . this conjugate is prepared from 40 according to the procedure described for conjugate 10 . having described the invention in detail and by reference to specific embodiments thereof , it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims . more specifically , although some aspects of the present invention are identified herein as preferred or particularly advantageous , it is contemplated that the present invention is not necessarily limited to these preferred aspects of the invention . female balb - c mice , at least 3 months of age , were used for immunizations . the immunogen contained 100 μg of the 6 - mam klh immunogen from example 9 per mouse emulsified in 50 % isotonic saline and 50 % freund &# 39 ; s adjuvant . complete freund &# 39 ; s adjuvant was used for the initial intraperitoneal ( ip ) immunization , and incomplete freund &# 39 ; s adjuvant was used for the remaining immunizations . the mice were reimmunized 30 , 84 , and 114 days after the initial immunization . the mouse selected for the fusion was given a booster immunization identical to immunizations two through four 509 days after the first immunization . four days later the immunized mouse was sacrificed , and its splenocytes were used in a cell fusion to produce monoclonal antibody secreting hybridomas . the mouse selected for fusion was killed via exsanguinations and cervical dislocation , and the spleen was aseptically harvested and ground between two sterile glass slides to release the lymphocytes . the resulting lymphocyte suspension was fused with the p3x63ag8 . 653 atcc cell line number crl 1580 ) myeloma line . viable lymphocytes were counted , and 20 % of that number of myeloma cells were added to the tube containing the mouse lymphocytes . the cells were washed in warm , serum - free iscove &# 39 ; s modified dulbecco &# 39 ; s media ( imdm ) by centrifugation , resuspension , and re - centrifugation . the centrifuge tube containing the resulting pellet was gently tapped to loosen the pelleted cells . one ml of warmed peg / dmso solution ( sigma chemicals ) was then slowly added to the cells while gently mixing . the cells were incubated at 37 ° c . for 1 . 5 minutes after which pre - warmed serum - free imdm was added at the following rates : 1 ml / min , 2 ml / min , 4 ml / min , and 8 ml / min . the tube was filled to 50 ml , capped , and incubated for 15 minutes at 37 ° c . the cell suspension was next centrifuged , the supernatant decanted , and the cells resuspended in hmt media . hmt media consists of complete imdm with condimed ( 77 . 9 % imdm , 10 % fcs , 10 % condimed h , 1 % l - glut , 1 % l - glut - pen / strep , 50 um 2 - mercaptoethanol , 40 μm ethanolamine ) with 50 × hmt diluted to 1 ×). the cells were resuspended at a concentration of 2 × 10 lymphocytes / ml , and 200 μl were pipetted into each well of 30 . 5 sterile , covered 96 - well microculture plates . the plates were incubated at 37 ° c . in 5 % co 2 tissue culture incubator for five days . on day six , 150 μl of supernatant was withdrawn from each well and was replaced with 150 μl of ht rescue media . ht rescue media consists of complete imdm with condimed plus 50 × ht supplement diluted to 1 ×. the plates were returned to the incubator and inspected daily for signs of growth . when cell colonies were sufficiently large , wells were screened for antibody production using an elisa . 96 - well microtiter plates were coated with 50 μl of 6 - mam - bsa conjugate from example 16 at 1 μg / ml in 0 . 1 m carbonate buffer , ph 9 . 5 for 1 hour at 37 ° c . ( humidified ). the plates were emptied , and 200 μl of post - coat solution consisting of ph 7 . 4 tris buffer , 1 % gelatin hydrolysate , 2 % sucrose , and 0 . 18 % tween 20 were added . the plates were incubated 1 hour at 37 ° c . ( humidified ). after the plates were emptied , 200 μl of a 2 % sucrose solution in 0 . 15m tris , ph 7 . 4 , was added . the plates were allowed to stand for approximately 5 minutes at room temperature and then were emptied and air dried overnight at room temperature . when dried , the plates were packed in zip - lock bags containing several desiccant pillows , sealed , and stored at 4 ° c . until use . when clones were ready for testing , 20 μl of supernatant from each well showing cell growth was taken and transferred to 96 - well flexible plates . pbst ( phosphate buffered saline , ph 7 . 0 , with 0 . 2 % tween 20 ) was added to each well to provide a 1 : 10 dilution of the supernatant sample . two 6 - mam - bsa coated wells were used for each culture well tested . one well received 25 μl of pbst buffer , the other received 25 μl of pbst containing 6 - mam at a concentration of 800 ng / ml . twenty - five microliters of the diluted sample were transferred to each pair of wells to assay supernatant antibody binding with and without free drug ( 6 - mam ) present . the plates were incubated in a humid chamber for 1 hour at 37 ° c ., after which they were washed with pbst . the wells were then filled with 50 μl of properly diluted goat anti - mouse igg - hrp conjugate and again incubated for 1 hour . the plates were washed again , and 50 μl of k - blue substrate was added . after a five minute incubation for color to develop , the reaction was stopped by the addition of 50 μl of 1 n hcl . color was read via a microplate reader at 450 nm , and data was transferred to a computer for analysis . supernatants that bound the 6 - mam - bsa conjugate ( produced color in the wells ) and showed significant inhibition of binding in the presence of free drug were considered positives , and the corresponding clones were subcloned . a total of 40 clones were selected for subcloning . subcloning was achieved by stringent cloning via limiting dilution . briefly , cells from the original well were counted , and a dilution was made so that 120 cells were added to 40 mls of complete imdm with 10 % condimed these cells were then dispensed into 2 sterile 96 - well plates , 200 μl per well . wells containing colonies that appeared to have grown from single cells were screened on 6 - mam coated elisa plates for binding in the absence of any free drugs and in the presence of morphine or codeine ( each at 80 ng / ml ). clones from selected wells ( positive for 6 - mam - bsa ) were then expanded in culture and frozen to create a cell bank . 6 - mam 9 . 3 was the third subclone selected from the 9 th clone identified in the original fusion plates . supernatant collected from 6 - mam 9 . 3 was titered on a 96 - well plate coated with 6 - mam - bsa at 0 . 1 μg / ml . the dilution for the supernatant which provided for 90 % of maximal od was 1 : 270 . 6 - mam 9 . 3 supernatant diluted 1 : 270 was then assayed on a 96 - well plate coated with 0 . 1 μg / ml of 6 - mam - bsa with different concentrations of free 6 - mam added to the well to generate the inhibition curve shown in fig8 . the ed 50 was determined to be 1 . 22e - 08 . that parameter which describes the concentration of the free drug which corresponds to 50 % of the binding in the absence of free drug is termed the ed 50 for that drug .
analogs of 6 - monoacetyl morphine are described . these include analogs derivatized at either the c - 3 position , the c - 6 position , or the nor position of the molecule . these analogs allow for elaboration with linkers terminated by a functional group such as an activated ester , the functional groups being useful for attaching the molecule to other entities such as proteins , polysaccharides , and reporter groups .