| abstract |
Prepn. if of benzazocine derivs. of formula (I), in racemic or optically active forms when R4 is not = R5 and/or R2 is not = R3, and their acid. addn. salts. Method comprises reacting cpds. of formula (II) with alcohols R2R3CHOH at 100-250 degrees C under 10-100 bars H2 in presence of a Ni and/or Co catalyst. (X and Y = CN or CH2NH2. R1, R2, R3 and R4 are each H or 1-6C alkyl; R6 = 1-6C alkyl). Opt. the initial prod. is O-dealkylated to give R1=H; racemates resolved and/or free bases converted to salts. (I) have pharmacological activity, esp. (I; R1=H) are powerful analgesics. A simple, single-stage, high-yield method is provided. In an example, a typical cpd., racemic-1,2,3,4,5,6-hexahydro-8-methoxy-3,6-dimethyl-3-benzazocin- e, was prepd. by reacting 3-(2-cyanomethyl-5-methoxyphenyl)-3-methylpentanonitrile and methanol under H2 over Raney Ni. |