Method for preparing pure optical isomer of 1.1'-bi-2-naphthol

摘要

The present invention provides a process for separating racemic mixtures of 1.1'-bi-2-naphthol represented by formula (I) into forms (S) and (R), which are optical isomers thereof. This method condensates the racemic mixture of general formula (I) with 2,2'-dimethylcyclopropanecarboxylic acid of general formula (II) to give 1.1'-bi-2-naphthol-mono-2,2-dimethylcyclo Obtaining a partial isomeric mixture (III) of propanecarboxylate and 1.1'-bi-2-naphthol-mono-2,2-dimethylcyclopropanecarboxylate; Recrystallizing the mixture (III) obtained in the above step and separating them from each other in form (S) and (R); And hydrolyzing these to obtain S-type compound (I) and R-type compound (I), respectively. According to the method of the present invention, compound (I) can be separated into its pure optical isomer in high purity and yield, and there is an advantage in that compound (II) can be regenerated and used.