Thiazoles from ethyl isocyanoacetate

Thiazoles from Ethyl Isocyanoacetate and Thiono Esters Ethyl Thiazole-... 

THIAZOLES FROM ETHYL ISOCYANOACETATE AND THIONO ESTERS ETHYL THIAZOLE-4-CARBOXYLATE... 

The mechanism of the condensation in Part D probably involves thioformylation of the metallated isocyanoacetate followed by intramolecular 1,1-addition of the tautomeric enethiol to the isonitrile. This thiazole synthesis is analogous to the formation of oxazoles from acylation of metallated isonitriles with acid chlorides or anhydrides. " Interestingly, ethyl formate does not react with isocyanoacetate under the conditions of this procedure. Ethyl and methyl isocyanoacetate have been prepared in a similar manner by dehydration of the corresponding IV-formylglycine esters with phosgene and trichloromethyl chloroformate, respectively. The phosphoryl chloride method described here was provided to the submitters by Professor U. Schollkopf and is based on the procedure of Bohme and Fuchs.The preparation of O-ethyl thioformate in Part C was developed from a report by Ohno, Koi/uma, and Tsuchihaski. 

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