The synthesis of D-9-clenbuterol (I) and D-3-clenbuterol (II) is described. D-9-clenbuterol (I) was prepared from 4-amino-alpha-bromo-3,5-dichloroacetophenone by reaction with D-9-tert-butylamine followed by reduction of the keto group with NaBH4. D-3-clenbuterol (II) was prepared from 4-amino-alpha-tert-butylamino-3,5-dichloroacetophenone by an exchange reaction of the alpha-hydrogens with deuterium followed by reduction of the keto group with NaBD4. The eventual products were characterized by mass spectrometry and NMR.
A method for the preparation of 1-(4'-amino-3',5'-dichlorophenyl)-2-alkyl)or dialkyl)aminoethanols. The method involves preparation of the above compounds from the corresponding aminoketones by reduction with hydrogen in the presence of platinum oxide catalyst and a promoter, such as stannous chloride.
The synthesis of D-9-clenbuterol (I) and D-3-clenbuterol (II) is described. D-9-clenbuterol (I) was prepared from 4-amino-alpha-bromo-3,5-dichloroacetophenone by reaction with D-9-tert-butylamine followed by reduction of the keto group with NaBH4. D-3-clenbuterol (II) was prepared from 4-amino-alpha-tert-butylamino-3,5-dichloroacetophenone by an exchange reaction of the alpha-hydrogens with deuterium followed by reduction of the keto group with NaBD4. The eventual products were characterized by mass spectrometry and NMR.