Patent ID: 8853401

Claim:
A process for preparing intermediates useful in the synthesis of morphinane and morphinone compounds comprising: (a) reacting a compound of the formula (II) with a compound of the formula (III) under conditions to form compounds of the formulae R-(Ia) and S-(Ib): wherein R 1 is selected from hydrogen, C 1-6 alkyl, C(O)C 1-6 alkyl and PG; R 2 is selected from R 3 , C(O)R 3 , S(O)R 3 and SO 2 R 3 ; R 3 is selected from C 2-6 alkyl, C 1-6 alkyleneC 3-8 cycloalkyl, C 1-6 alkyleneC 6-10 aryl, C 1-6 alkyleneC 1-8 heterocyclyl and C 1-6 alkyleneC 1-10 heteroaryl; LG is a leaving group; PG is a protecting group; Z is a suitable counter anion; and each alkyl, alkylene and aryl is optionally fluoro-substituted and/or deuterated; and (b) isolating the compound of the formula R-(Ia); and (c) treating the remaining side products, including the compound of the formula S-(Ib) and a mixture of the compounds of the formulae R-(Ia) and S-(Ib) under N-demethylation conditions to form a compound of the formula (IV): wherein R 1 is selected from hydrogen, C 1-6 alkyl, C(O)C 1-6 alkyl and PG; R 2 is selected from R 3 , C(O)R 3 , S(O)R 3 and SO 2 R 3 ; R 3 is selected from C 2-6 alkyl, C 1-6 alkyleneC 3-8 cycloalkyl, C 1-6 alkyleneC 6-10 aryl, C 1-6 alkyleneC 1-8 heterocyclyl and C 1-6 alkyleneC 1-10 heteroaryl; PG is a protecting group; and each alkyl, alkylene and aryl is optionally fluoro-substituted and/or deuterated.