反应详情

A solution of 20.26 g (53.8 mmol) of (+)-dibenzoyl-D-tartaric acid monohydrate in 110 ml of an acetone/water (4:1) mixture was added to a solution of 16.21 g (53.8 mmol) of the (±)-N-methyl-1-(2-methylimidazo[1,2-a]pyridin-6-yl)-2-oxocyclohexanecarbothioamide prepared in the Example 5 in 900 ml of an acetone/water (4:1) mixture. The obtained mixture was allowed to stand at room temperature for 2 hours, giving (+)-N-methyl-1-(2-methylimidazo[1,2-a]-pyridin-6-yl)-2-oxocyclohexanecarbothioamide (+)-dibenzoyl-D-tartrate as a colorless prism crystal. This crystal (14.6 g, 95% ee or above) was filtered out.