Oxygen → 1-Methyl-1-oxophospholanyl methyl phosphinic acid methyl ester
Reaktionsgleichung
[CH3:1][P:2]1(=[O:7])[CH2:6][CH2:5][CH:4]=[CH:3]1.O=O.[CH3:10][O:11][P:12]([CH3:14])[OH:13]>>[CH3:10][O:11][P:12]([CH:3]1[CH2:4][CH2:5][CH2:6][P:2]1([CH3:1])=[O:7])([CH3:14])=[O:13]Komponenten
4
Versuchsvorschrift
6 g of tert.-butyl peroctoate in 30 g of methane phosphonous acid methyl ester and 116 g of 1-methyl-1-oxophospholine are added dropwise to 282 g of oxygen-free methane phosphonous acid methyl ester at 120° C. with stirring. The reaction time is 90 minutes. Excess methane phosphonous acid methyl ester and a small quantity of 1-methyl-oxophospholine are distilled off. The residue, consisting of 205 g of 1-methyl-1-oxophospholanyl-methyl phosphinic acid methyl ester is purified by distillation under vacuum (bp1 mm : 210° to 220° C.) to yield 186 g of pure product which solidifies very slowly to stellate crystals which begin to reliquefy at 70° C. Acid saponification leads to isomeric 1-methyl-1-oxophospholanylmethyl phosphinic acids of the idealized constitution: ##STR17##