Synthesis of novel mesoionic systems: 1,3-oxathiolylium-4-thiolate and 1,3-oxazolylium-4-thiolate. A synthon allowing a new approach to 1,4-oxathiafulvene derivatives

Abstract

By a convenient one pot reaction, dialkylamino(thiocarbonyloxy)phenylacetic acids (1) are converted into the novel 1,3-oxathiolylium-4-thiolates (6) or 1,3-oxazolylium-4-thiolate system (4) in high yields; the former mesoionic heteroarenes (6) readily combine with CH acidic compounds to give 1,4-oxathiafulvene derivatives (7) or (8).