抄録
3, 4, 5-Trichloropyridazine on treatment with 2-aminothiophenol gave 4-chloro-10H-benzo[b]pyridazino[3, 4-e][1, 4]thiazine (II) and 1-chloro-10H-benzo[b]pyridazino[4, 5-e][1, 4]-thiazine (III). II was converted into 10H-benzo[b]pyridazino[3, 4-e][1, 4]thiazine by catalytic dechlorination. Treatment of 4, 5-dichloro-3-(2H)-pyridazinone with 2-aminothiophenol afforded 5-(2-aminophenylthio)-4-chloro-3(2H)pyridazinone, which was cyclized on heating with potassium carbonate in dimethylformamide to yield 10H-benzo[b]pyridazino[4, 5-e][1, 4]thiazin-1(2H)-one. Chlorination of the latter with phosphoryl chloride and N, N-dimethylaniline afforded III. Several 2-substituted-10H-benzo[b]-pyridazino[4, 5-e][1, 4]thiazin-1(2H)-ones were synthesized.
