[amino(ethoxy)phosphoryl]oxyethane

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 6,7-dimethyl-3,4-dihydro-1H-2-benzothiopyran-4-one-1-carboxylic acid (0.945 g) in THF (10 ml) were added oxalyl chloride (0.609 g) and DMF (2 drops), and the mixture was stirred at room temperature for 1 hour. On the other hand, a mixture of diethoxyphosphorylamine (4.9 g), sodium hydride in oil (60%, 0.32 g) and THF (30 ml) was stirred with ice-cooling for 30 minutes and, then, the above solution was added. The mixture was stirred with ice-cooling for 30 minutes, poured into water and extracted with ethyl acetate. The ethyl acetate layer was washed with water, dried (MgSO4) and the solvent was distilled off to give N-diethoxyphosphoryl-6,7-dimethyl-3,4-dihydro-1H-2-benzothiopyran-4-one-1-carboxamide (0.29 g, 19%). Recrystallization from ethyl acetate gave colorless prisms melting at 192°-1931/2° C. was stirred with ice- cooling for 30 minutes the above solution was added The mixture was stirred with ice- cooling for 30 minutes extracted with ethyl acetate The ethyl acetate layer was washed with water dried (MgSO4) the solvent was distilled off