EACTION of 3-methyl-2-benzothiazolinone hydrazone (1) with ...... some selected isocyanate and isothiocyanate reagents 2a-j gave the respective semicarbazones and thiosemicarbazones 3a-j.Thermolysis of compound 3a under reduced pressure gave N,N`-diethylurea 4) in addition to 1,2-bis (3-methylbenzo[d]thiazol-2(3H)-ylidene)hydrazine (5).Compound 3a was almost quantitatively recovered upon its expos...