RECYCLING PROCESS FOR INCREASING THE YIELD OF A GRIGNARD REACTION IN THE PREPARATION OF OPIATE ALKALOID DERIVATIVES

摘要

Process for increasing the yield of opiate alkaloid derivatives of Formula(II) or(IIa), wherein the process comprises forming the compound of Formula (II) or(IIa) viaa Grignard addition reaction, crystallizing the compound of Formula (II) or(IIa) from amixture also comprising unreacted starting compound, and recycling theunreactedcompound to subsequent addition reactions. The compound of Formula (II) or(IIa):(see formula II or IIa).