A NEW ROUTE TO 2H-(1,2,4) TRIAZINO(3,4b) BENZOTHIAZOLE-3(4H)-ONE¹ (4)

Abstract

The reaction of 3-(carbethoxymethyl) benzothiazoline-2-thione (1) with excess hydrazine in an aqueous medium at 25–30° or 95–100°C afforded the hydrazide (3) in 99% yield and the titled heterocyclic compound (4) in 63% yield, respectively. Under the same reaction conditions and replacing the above electrophile with 3-(carbethoxymethyl)-2-benzothiazoline furnished the hydrazide (5) in 45% yield and a 6% yield of 5 plus a high yield of a resinous mixture, respectively. Possible mechanism and supporting NMR and mass spectral data are discussed.