New Methods for the Synthesis of 2-Aminothiazolones
摘要:
[GRAPHICS]Two new methods for the synthesis of 2-aminothiazolones from 2-(4-methoxybenzylthio)acetic acids are described. A single reagent and simple experimental conditions are used in the key tandem deprotection-cyclization process. In the first approach 2-aminothiazolones are directly accessed via cyclization of the corresponding N-acylisothioureas. The second complementary approach provides access to a variety of 2-thiomethylthiazoiones via cyclization of N-acyldithioimidates. The product 2-thiomethylthiazol ones are then efficiently converted to 2-aminothiazolones via amine displacement.
A highly efficient one-pot synthesis of thiazolidin-4-ones via [3+2] cycloaddition of aza-oxyallylic cations with isothiocyanates is developed. The aza-oxyallyic cations were generated in situ in the present of a base. This cycloadditionreaction allows the rapid access to a variety of thiazolidin-4-one derivatives in mild conditions, good yield, and excellent functional group compatibility.