Studies on organophosphorus compounds. Synthesis and reactions of 1,2,4-triazolo(4,3-d)-1,3,4,2-benzo-oxadiazaphosphopine and triazaphosphopine derivatives

2,4-Bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4-disulphide (Lawess on's Reagent, LR) reacted with 4-amino-3-mercapto-5-(o-hydroxyphenyl and/or o-aminophenyl)-1,2,4-triazoles (1a and 2a) in boiling acetonitrile to affo rd s-triazolo(4,3-d)-1,3,4,2-benzo- oxadiazaphosphopine-6-sulphide (3a) and triazaphosphopine-6-sulphide (4a) derivatives, respectively. Compounds 3a and 4a were alkylated with methyl iodide, benzyl chloride, ethyl chloroacet ate and/or chloroacetanilide to give the corresponding s-alkylated derivati ves (3b-e and 4b-e, respectively). The structures of the products were prov ed chemically by the preparation via condensation of LR with the correspond ing 3-alkylthio-4-amino-5-aryl-1,2,4-triazoles (1b-e and 2b-e). Also, the s tructures of all new compounds were elucidated on the basis of elemental an alysis, IR, H-1-NMR, and MS spectra.