Patent ID: 8455509

Claim:
A process for the preparation of morphine compounds of the formula (I): wherein: R1 is selected from the group consisting of a hydrogen atom and a hydroxyl group; and R2 is selected from the group consisting of a hydrogen atom, (C 1 -C 6 )alkyl group, cyclo(C 3 -C 6 )alkyl group and (C 2 -C 6 )alkenyl group; comprising a low content of α,β-unsaturated compounds, comprising the stages of: (i) bringing the crude morphine compound into contact with a base, at a pH of greater than 13, under conditions which make possible the Michael addition reaction on the α,β-unsaturated compound(s) present; (ii) separating the morphine compound from the reaction mixture; and (iii) if appropriate, separating the addition product formed from the morphine compound.