Acid-Catalyzed Synthesis of Thiazolidin-4-ones

ABSTRACT

A two-steps synthesis of thiazolidin-4-ones, from α-tetralone 6 or thiochroman-4-one 7, catalyzed by acids is described. The reactions of α-tetralone 6 or thiochroman-4-one 7, with substituted thiosemicarbazides, under AcOH or heteropolyacid (HPAs) catalysis afford thiosemicarbazones 8 and 9 in excellent yields. Condensations of the previous compounds 8 and 9 with α-bromoester, under sulfuric acid or heteropolyacid catalysis, yield the corresponding thiazolidin-4-ones 10 and 11.

KEYWORDS:

• α-tetralone
• cyclization
• thiazolidin-4-ones
• thiochroman-4-one
• thiosemicarbazone