Reaktion #62034

Reaktionsgleichung

isothiocyanate

thiophosgene

cyanoacetamide

aniline

p-amino benzoic acid

→

2-(4-aminophenyl)benzoxazole

benzothiazole

benzimidazole

thiocarbamoyl cyanoacetamide

Reaktionsbedingungen

Vorschrift

The 2-(4-aminophenyl)benzoxazole, benzothiazole, or benzimidazole was prepared by condensation of the appropriate aniline derivative with p-amino benzoic acid using polyphosphoric acid. The product was converted to the corresponding isothiocyanate with thiophosgene and subsequently condensed with cyanoacetamide to form the thiocarbamoyl cyanoacetamide. Treatment with bromine afforded the cyano hydroxy thiazole, which was converted to carboxamidine by treatment with the appropriate amide, as shown above.

Quelle