Process for unprotected asymmetric preparation of nicotine

Abstract

The present disclosure relates to an asymmetric process for preparing nicotine without protection, in particular to a process for preparing optically pure nicotine by taking nicotinate as a starting material and carrying out four-step reaction. The process comprises the following steps: nicotinate and γ-butyrolactone are subjected to condensation reaction, asymmetric catalytic reduction reaction, activation, and reaction with methylamine to give optically pure nicotine. The asymmetric catalytic reduction for preparing the chiral alcohol intermediate compound with high optical activity is a key step of the method. The method of the present disclosure has the characteristics of high atom economy, very high reaction activity, capability of keeping excellent stereocontrol, capability of obtaining a chiral product with very high enantioselectivity, short reaction steps, low cost of raw materials, green and pollution-free, capability of greatly reducing the quantity of “three wastes”, and easiness in realizing industrial amplification production.

Dependencies are inferred from the claim text.