Synthetic and Thermogravimetric Studies of 5-Amino-2-ethoxycarbonylaminothiazoles

Abstract

5-Amino-4-cyano-2-ethoxycarbonylaminothiazole (2), 2-ethoxycarbonylaminothiazolo[5,4-d]pyrimidine-7(6H)-one (4), and 5-ethoxymethyleneamino-4-cyano-2-ethoxycarbonylaminothiazole-4-carboxamide (9) were synthesized from 5-amino-2-ethoxycarbonylaminothiazole-4-carboxamide (1). Unlike simple 5-aminothiazoles, 1 and 2 did not undergo rearrangement in hot aqueous alkali, because of the role of their 2-ethoxycarbonylamino substituents. Thermogravimetric experiments on 1, 2, 4, and 9 revealed routine elimination of ethanol molecule from the NHCO ₂C₂H₅ substituent of 1, 2, 4, and 9.

GRAPHICAL ABSTRACT

Keywords:

• 5-Amino-2-ethoxycarbonylaminothiazoles
• thermal elimination of ethanol
• thermogravimetric studies
• thiazolo[5,4-d]pyrimidine

ACKNOWLEDGMENTS

We thank P. Ghosh for ¹H NMR and ¹³C NMR spectral measurement. One of the authors (P. K. Ray) is thankful to the University Grants Commission, New Delhi, for a research fellowship.