DERIVES THIOPHOSPHORYLES DE LA BIS(2-CHLOROETHYL)AMINE PREPARATION D'ALKOXY-2 OXO-2 CHLOROETHYL-3 THIAZAPHOSPHOLIDINE-1,3,2

Abstract

The reaction of bis(chloroethyl-2)amine with dimethylthiochlorophosphate in anhydrous methylene chloride proceeds by an initial quantitative P[sbnd]N bond formation rapidly followed by a spontaneous exothermic intramolecular cyclisation to a thiazaphospholidine ring. Using higher alkyl thiochlo-rophosphates as starting materials the thiophosphoramidates were first obtained; cyclisation is done either by pyrolysis or by heating in CH₃CN. All the thiazaphospholidine rings undergo cleavage of the P[sbnd]N bond in aqueous acetone. Direct ³¹P NMR monitoring of the formation of thiazaphospholidines reveals unambiguously the invervention of a phosphonium P(IV)⁺ intermediate which suggests that the reaction mechanism is of the Michaelis-Arbuzov type.

La condensation de la bis(2-chloroethyl)amine sur le O,O-dimethylthiochlorophosphate conduit à la formation quantitative de thiophosphoramide qui simultanément se réarrange exothermiquement en thiazaphospholidine. L'emploi de thiochlorophosphates homologues fournit des thiophosphoramides de moindre réactivité dont la cyclisation n'est réalisable que par pyrolyse à haute température. L'examen en RMN de ³¹P du déroulement de chacune des réactions a révélé l'existence d'une intermédiaire phosphonium P(IV)⁻ postulé dans les réactions de type Michaelis-Arbuzov.