A novel four- and pseudo-five-component reaction: unexpected efficient one-pot synthesis of 4H-thiopyran derivatives.

A facile and convenient novel method is reported for the synthesis of substituted 4H-thiopyrans by reacting aldehydes, malononitrile, carbon disulfide, and primary amines at room temperature in the presence of triethylamine as a catalyst. This reaction affords the desired products in high purity and has advantages of excellent yields, simple work-up procedure, and short reaction time.