Self-condensation of arylthioacetamides: novel syntheses of 3-aminothioacrylamides, 2,4-diaminothiophenes and four-membered-ring vinamidinium salts
Abstract
Self-condensation of arylthioacetmorpholides 1 in the presence of N,N-disubstituted amides 2 and POCl3 gave 2-aryl-3-benzyl-3-morpholinothioacrylamides 4, which were converted to four-membered-ring vinamidinium salts 5 or 2,4-dimorpholino-3,5-diarylthiophenes 6 by novel synthesis of the thiophene ring.