Abstract
Cyclization of tosylmethyl isocyanide with α-oxodithioesters in the presence of KOH
is reported for the synthesis of 4-methylthio-5-acylthiazoles. Similarly, ethyl isocyanoacetate
underwent cyclization with α-oxodithioesters to form 4-ethoxycarbonyl-5-acylthiazoles
in the presence of DBU/EtOH. Mechanisms for the formation of thiazoles are proposed.
These thiazoles can also be obtained by Takeda reaction, in which thiazole-4,5-anhydride
is acylated with aromatic compounds followed by esterification; however, that approach
requires two steps and suffers from the formation of a regioisomeric mixture of products.
Key words thiazole - TosMIC - ethyl isocyanoacetate - α-oxodithioester - cyclization
