Function of 2-aminobenzoxazole with aroylisothiocyanates gave 2-aroylaminob
enzoxazoles (3) and N-aroyl-N'-(benzoxazol-2-yl) thioureas (4). The product
s obtained on reaction of 4 with PCl5 in POCl3 and with oxidizing agents ha
ve been identified as 3-aroylimino benzoxazolo [3,2-b] [1,2,4]-thiadiazolin
es (6).