Properties<unk>  has a catechol structure similar to that of dopamine. Synthesis Several techniques exist for the creation of<unk>  from morphine. In the past, morphine had been combined with hydrochloric acid at high temperatures (around 150 °C) to achieve a low yield of<unk> , ranging anywhere from 0.6% to 46%. More recent techniques create the<unk>  in a similar fashion, by heating it in the presence of any acid that will promote the essential dehydration rearrangement of morphine-type alkaloids, such as phosphoric acid. The method then deviates by including a water scavenger, which is essential to remove the water produced by the reaction that can react with the product and lead to decreased yield. The scavenger can be any reagent that will irreversibly react with water such as phthalic anhydride or titanium chloride. The temperature required for the reaction varies based upon choice of acid and water scavenger. The yield of this reaction is much higher: at least 55%.Conversion of Morphine (I) to<unk>  (II) in the presence of acid following the example of the morphine skeleton dehydration rearrangement, outlined by Bentley.
Apomorphine
Desomorphine
Tripelennamine
Droperidol
Tropisetron
Amfepramone
Benzatropine
Bremazocine