SU1432056A1 - Method of producing trimethylsilyl-substituted amides of dialkylphosphinic acids - Google Patents

Abstract

The invention relates to the chemistry of organophosphorus compounds, in particular to the preparation of N-shtyl-substituted amides of dialklphosphonous acids of the formula P1Sh31 (CH3) e, where R and B are lower alkyls. The goal is to simplify the process and expand its scope. Obtaining the desired compounds are from hexamethyldisilylamine and dialkyl chlorophosphine (LCF) at a molar ratio of (2-4); 1 in the presence of a catalyst. As the latter, a hydrochloric.-Nitride base or ammonium chloride is used - 3-5 mol.% Based on the AHF at the boiling point in an inert gas atmosphere. Preferably, in the case of using AChF with primary radicals, the process is carried out in a toluene medium. The yield increases by 10-20%. 1 hp f-ly. (On the cl "Od Nd Oi Od

Description

This invention relates to the chemistry of organophosphorus compounds, namely, to a new method for the preparation of H-silkza ™ of methyl amine dna alkylphosphinist acids of the general formula

(I)

RfRjPHSi (CH3) 3

where R. and Rj are lower alkyls.

These compounds have two nucleotide centers — phosphorus and nitrogen atoms, as well as a highly reactive bond, which makes them valuable intermediates for organic and elemental-organic synthesis.

The chain of the invention is the simplification of the method for the synthesis of N-C 1-6 substituted amides of dialkyl 5 -phosphonyl acid and an increase in their yield, as well as the possibility of obtaining previously unavailable compounds with both primary phosphorus using this method.

5 Kazan goal is achieved by the interaction of dialkylphosphines of the formula

Rjplc

(where R.

and R is lower alkyl; with hexamethyldisilylamine with a molar ratio of reagents of 1 g; 2-4 in npKcyTCTBifH as a catalyst for the hydrochloride of a nitrogenous base (e.g., triethylamine or pyridine) or aconium chloride, taken in an amount of 3-5 mol.% Based on the starting alkyl chloride chlorine phosphate, at tempered boiling of the mixture in an inert gas atmosphere.

Dp dialkyl chlorophosphines with both primary alkyls R and R for the implementation of a better mixing of the reaction mixture, the process is carried out in an inert solvent, for OCtalny R, 2.01 is enough excess hexamethyldisilylamine (PCP).

The use of HMDS in an amount of less than 2 mol per mole of dialkyl chlorophosphine, leading to a decrease in the yield of the target products due to the side formation of imides of diaztylphosphine acids of formula (.) Ira, and the amount of more than 4 mol is not; influences the course of the reaction and the yield of the targeted compounds.

In the absence of a catalyst, it is not possible to obtain H-silyl-substituted amides of dialkylphosphonic acids I. The indicated temperature range (llO-iaS C) provides the most selective effect of the catalyst. An increase in temperature above 125 ° C leads, especially in the case of

five

0

five

ABOUT

Q.

0

R and R .j are primary alkyls, to a decrease in the yield of the target product due to its thermal disproportion on the imide of the formula () 2NH and hexamethyldisilamine,

All operations are carried out in a stream of dried argon.

Example 1. DG-Trimethylsilyl-amide of distilphosphinic acid (la). To a mixture of 45 g (0.28 mol) of HMDS, 20 mp of toluene and 0.4 g (0.0035 mol) of pyridine hydrochloride is added dropwise with stirring in 15 minutes a solution of 8.4 g (0.07 mol a) dicythylchlorophosphine in 20 ml of toluene. A white precipitate is observed. The reaction mixture is heated for 10 minutes at 0 ° C, at which time the precipitate dissolves. An excess of HMDS was removed on a column in a vacuum of 20 mm Hg, st., The residue was distilled from a Klysen flask with a reflux condenser of 20 cm, 8.25 g (66%) of amide (la) were obtained with t, kip, (P mm RT st,), p 1.4525, dip 32.5 ppm

Found,%: C 47; 49; H 11.48.

C H pNPSi.

Calculated,%: C 47.35; H 11.31.

Example 2, N-Trimethylsilyl-amide diisopropylphosphonic acid (16). 16.75 g (0.104 mol) of HMDS and 7.9, g (0.052 mol) of diisopropyl chlorophosphine and 0.3 g (0.0025 mol) of pyridine hydrochloride are heated 10 hours at 125 ° C, 0.2 g of hydride is added Calcium and heat the mixture for another 30 minutes, then the excess HMDS is removed in vacuo, distilling the residue to yield 7.9 g (74%) of the amide (1b) with a bp. 69-70 C (9 mm Hg), 1.4580, 4 47j5 ppm

Found,%: C 52.80; H 11.41.

.

Calculated,%: C 52, 56; H 11.26.

Example 3. S-trimethylsilyl-amide of isopropyl tert-butylphosphonic acid (IB), 8.3 g (0.05 mol) of isopropyl tert-butyl chlorophosphine, 24.1 g (0.15 mol) of HMDS and 0.15 g (0.0025 mol) ammonium chloride is heated for 5–6 h with ammonium chloride filtered off, the hMDS is removed under vacuum, and 7.9 g (72%) amide (Tv) are obtained by distillation of the residue with a boil. 76--77 ° C (8 mmHg), nj 1.4610, cfp 55 ppm.

Found,%: C 54.48; H 12.10,

C | (, HjgNPSi.

Calculated,%: C 54.75; N.

W 14320564

Claims (2)

The invention is a phosphine with a molar ratio of reagents of 2-4: I and a process Be1. A method for producing N-trimethylsi-dut in the presence of a hydrolytic amide of dialkylphosphinisyl chloride of aero-base or tic acids using dialkyl chloride, ammonium, taken in the amount of chlorophosphine and organosilicate, 3–5 mol,% based on dialkyl chloro compound, which differs in phosphine, at the boiling point, we estimate that, in order to simplify the process in an inert gas atmosphere. and expanding its scope, 2. The method of pop. 1, which differs in the quality of organosilicon soya and with the fact that, in the case of its use, hexamethyldisilylide dialkylchlorofrfenes are used with the first amine, which is subjected to direct radicals, with dialkyl chloro-environment toluene.