A novel fused phosphorus heterocycle:: 4-(1′, 2′, 3′, 4′-tetrahydro-1, 3, 2-benzodiazaphosphorin-2′-sulfide)-3, 4b, 4a-thiazphosphaphenanthridine derivative

The first example of fused phosphorus heterocyclic 4-[1'-(beta-bromoethyl)-4'-oxo-3'-prop yl-1', 2', 3', 4'-tetrahydro-1, 3, 2-benzodiazaphosphorin-2'-sulfide]-1, 2, 3, 4, 4a, 4b, 5, 6-octahydro -6-oxo-5-propyl-3, 4b, 4a-thiazphosphaphenanthridine 4a, 2'-dioxide was synthesized in excellent yield by refluxing a mixture of 1-(2-bromoethyl)-2, 3-dihydro-3-propyl-1, 3, 2-benzodiazaphos phorin-4(1H)-one 2-oxide with carbon disulfide in benzene in the presence of triethylamine.