Novel reaction of N,N'-bisarylmethanediamines with formaldehyde. Synthesis of some new 1,3,5-triaryl-1,3,5-hexahydrotriazines.
The acid-catalyzed cyclocondensation of N,N'-bisaryl (aryl = 2-pyrimidinyl, 2-pyrazinyl and 4-nitrophenyl) methanediamines 5a-c with aqueous formaldehyde in refluxing acetonitrile leads to the formation of the corresponding 1,3,5-triaryl-1,3,5-hexa-hydrotriazines 6a-c. The stoichiometric reactions of 2-aminopyrimidine and 2-amino-pyrazine with aqueous formaldehyde in acetonitrile under reflux conditions also afforded 6a and 6b, respectively. Treatment of 2-aminopyrimidine with aqueous formaldehyde in a 3:2 ratio yielded N,N',N"-tris(2-pyrimidinyl)dimethylenetriamine (7a) as a sole product, which upon subsequent reaction with formaldehyde also afforded 6a. The reaction of N,N'-biphenylmethanediamine with formaldehyde was also investigated.
Synthesis of racemic cis and trans 2,4,5-tripyridylimidazolines
Abstract Reaction of 2-pyridinecarboxaldehyde with ammonium hydroxide gives 1,3,5-triazine 6 which was converted to cis-2,4,5-tripyridylimidazoline, 9 . The intermediate 2,4-diazapentadiene is not observed, but believed to undergo deprotonation and cyclization to afford cis-2,4,5-tripyridylimidazoline. Base catalyzed isomerization (5 mol% KO-t-Bu, 23°C) of cis-2,4,5-tripyridylimidazoline gives trans-imidazoline ( 10 ). Compounds 6 , 9 , and 10 have been characterized by X-ray crystallography.
The development of a liquid antihistaminic preparation with sustained release properties.
The relative capacity of several cation exchange resins to adsorb methapyrilene has been determined by an in vitro method. It was demonstrated that methapyrilene adsorbed on sulfonic acid cation exchange resin possessed pharmacological activity approximating that of a solution of methapyrilene hydrochloride as measured by the protection against histamine-induced asthma in the intact guinea pig. It is suggested that the use of ion exchange resins as carriers of drugs in liquid dosage forms may be useful in sustained release preparations.