Patent ID: 8168790

Claim:
A process for preparing a compound, the process comprising: (a) contacting a 6-keto morphinan compound comprising Formula (I) with a reducing agent, a first proton acceptor and a solvent, wherein the concentration of the 6-keto morphinan of Formula (I) in the solvent is at least 25 grams per liter, to form a first homogeneous reaction mixture, wherein some of compound (I) is converted to a 6-hydroxy morphinan compound comprising Formula (II) to produce a substantially heterogeneous reaction mixture; and (b) contacting the heterogeneous reaction mixture with a second proton acceptor to form a second homogeneous reaction mixture, wherein some of compound (I) that was not converted to compound (II) in step (a) is converted to compound (II), the process of steps (a) and (b) proceeding according to the reaction scheme: wherein: R is chosen from hydrogen, hydrocarbyl, substituted hydrocarbyl and hydroxy protecting group; R 1 is chosen from hydrogen, hydrocarbyl, and substituted hydrocarbyl; R 2 and R 3 are independently chosen from hydrogen, OH, NH 2 , SH, hydrocarbyl, substituted hydrocarbyl, alkyl ketal, alkyl thiol ketal, and alkyl dithiol ketal, wherein when R 1 and R 2 are different they form an epimeric pair, and wherein R 1 and R 2 together may form a group chosen from cycloalkyl ketal, cycloalkyl thiol ketal, and cycloalkyl dithiol ketal; R 4 , R 5 , R 6 , and R 7 are independently chosen from hydrogen, halogen, NH 2 , CN, SH, CF 3 , OR 9 , hydrocarbyl, and substituted hydrocarbyl; R 8 is chosen from hydrogen and hydroxy; and R 9 is chosen from hydrogen, hydrocarbyl, substituted hydrocarbyl, and hydroxy protecting group.