An Efficient Method for the Preparation of 4-Alkoxy-substituted Thieno[2,3-b]pyridines
摘要:
An efficient method for the preparation of 4-alkoxy-substituted thieno[2,3-b]pyridines is described. The key intermediates, 4-alkoxy-2-chloro-3-cyanopyridines, were synthesized from a variety of alcohols by nucleophilic substitution with 3-cyano-2,4-dichloropyridine or by Mitsunobu reaction with 2-chloro-4-hydroxynicotinonitrile. Subsequent reaction of 4-alkoxy-2-chloro-3-cyanopyridines with 2-(acetylthio)acetamide under basic conditions provided 4-alkoxy-substituted thieno[2,3-b]pyridines in fair to good yields.