Patent ID: 8258298

Claim:
A process for preparing morphine-6-glucuronide or a derivative thereof, comprising: (i) reacting a compound of formula (I): wherein: R 1 represents a carbonyl group, COR 5 CO in which R 5 represents a group (C 1 -C 4 )alkane-diyl, (C 2 -C 4 )alkene-diyl, (C 2 -C 4 )alkyne-diyl, hetero(C 1 -C 4 )alkane-diyl, heterocyclo(C 3 -C 6 )alkane-diyl, (C 5 -C 14 )arene-diyl, bi(C 10 -C 16 )arene-oxide-diyl, bi(C 10 -C 16 )arene-diyl, or hetero(C 4 -C 10 )arene-diyl, SO 2 R 6 SO 2 in which R 6 represents a group (C 1 -C 4 )alkane-diyl, (C 2 -C 4 )alkene-diyl, (C 2 -C 4 )alkyne-diyl, hetero(C 1 -C 4 )alkane-diyl, heterocyclo(C 3 -C 6 )alkane-diyl, (C 5 -C 14 )arene-diyl, hetero(C 4 -C 10 )arene-diyl, bi(C 10 -C 16 )arene-oxide-diyl or bi(C 10 -C 16 )arene-diyl; with a glucuronic acid derivative corresponding to formula (II): wherein: PG represents an acetyl, isobutyryl, benzoyl or pivaloyl group, X represents a trihaloacetimidate group, and R 4 represents a group (C 1 -C 4 )alkylcarboxylate; in the presence: of an aromatic solvent that is unsubstituted or substituted with one or more substituents chosen from the group formed by a halogen atom, a group (C 1 -C 4 )alkyl and a group (C 1 -C 4 )alkyloxy, said solvent having a melting point of less than or equal to −20° C., and of trimethylsilyl trifluoromethanesulfonate; (ii) reacting the product obtained in step (i) with a strong basic agent; and then (iii) recovering the product obtained in step (ii).