反应详情

温度

50 °C

0.20 mol (63.4 g) 4-ethyl-4-methyl-3-oxo-1-aminohexane-1,1-di-phosphonic acid (IV) R2 =R3 =CH2CH3, R4 =CH3) were suspended in 600 ml 2N hydrochloric acidd and a solution of 0.8 mol (55.2 g) sodium nitrite dissolved in 1104 ml water were added dropwise to the resulting suspension with stirring over a period of 7 hours at 50° C. 2-Ethyl-2-methyl-butyric acid was formed as the organic phase and was extracted with ether. Unused nitrous acid was removed with hydrazine before working up. The aqueous phase was concentrated to around 300 ml in a rotary evaporator and alkylized to pH 9 with sodium hydroxide. The tetrasodium salt of hydroxyacetonitrile diphosphonic acid (III, M=Na) crystallized out from the cold solution in the form of the octahydrate. The yield comprised 65% (58.4 g).

1. additionwere added dropwise to the resulting suspension