Preparation method of dialkyl methylphosphonite

A technology of dialkyl methyl phosphinate and methyl phosphine dichloride is applied in the field of metal organic compound preparation, which can solve problems such as the decomposition of diethyl methyl phosphinate, achieve no three-waste discharge, improve efficiency, Safe and stable effect of reaction conditions

Active Publication Date: 2016-09-21
庄建元
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

USP2,903,475 leads ammonia to keep pH7.0~8.5 and is difficult to control, because MePCl The reaction with alcohol is not instantaneously completed, for example when measuring the pH8.0 of system, there is still unreacted MePCl in the system, still will produce hydrogen chloride, and Excessive ammonia gas will also lead to the decomposition of diethyl methylphosphinate
USP3,057,904 and USP3,911,059, due to the pKa 5.15 of N,N-dimethylaniline and pKa 6.61 of N,N-diethylaniline, even if there is a small amount of hydrochloride of these two weak bases, when distilled by heating When diethyl phosphonate is decomposed, hydrogen chloride is decomposed, resulting in the decomposition of diethyl methylphosphonite

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] Example 1. Dimethyl methylphosphonite

[0038] 1) Feeding

[0039] Nitrogen protection in the four-necked reaction flask. Anhydrous MeOH 67.3g (2.1mol), anhydrous tri-n-propylamine 315.2g (2.2mol) and 40-60°C petroleum ether 2400g were placed at the bottom of the reaction bottle and heated to 25°C.

[0040] 2) Reaction

[0041] 118g (1.0mol) of 99% MePCl2 was diluted with 300g of petroleum ether at 40-60°C, and was added dropwise into the reaction bottle under vigorous stirring. The dropwise addition process was 2 hours, during which the temperature in the bottle was maintained at 25±2°C. After the dropwise addition, keep stirring at 25±2°C for 1 hour. Cool to 15 ° C, ready to drop lye.

[0042] 3) neutralize

[0043] 2.1 mol of 20% by weight NaOH aqueous solution was stirred and dropped into the cooling water outside the reaction flask to maintain the temperature inside the flask at 15±2°C. After dripping the NaOH solution, stir vigorously for 5 minutes (pH shoul...

Embodiment 2

[0046] Example 2. Diethyl methylphosphonite

[0047] 1) Feeding

[0048] Nitrogen protection in the four-necked reaction flask. Anhydrous EtOH 96.6g (2.1mol), anhydrous Et3N 222.6g (2.2mol) and 40-60°C petroleum ether 2400g were placed at the bottom of the reaction bottle and heated to 25°C.

[0049] 2) Reaction

[0050] 118g (1.0mol) of 99% MePCl2 was diluted with 300g of petroleum ether at 40-60°C, and was added dropwise into the reaction bottle under vigorous stirring. The dropwise addition process was 2 hours, during which the temperature in the bottle was maintained at 25±2°C. After the dropwise addition, keep stirring at 25±2°C for 1 hour. Cool to 15 ° C, ready to drop lye.

[0051] 3) neutralize

[0052] 2.1 mol of 20% by weight NaOH aqueous solution was stirred and dropped into the cooling water outside the reaction flask to maintain the temperature inside the flask at 15±2°C. After dripping the NaOH solution, stir vigorously for 5 minutes (pH should be 9), all t...

Embodiment 3

[0055] Example 3. Diisopropyl methylphosphonite

[0056] 1) Feeding

[0057] Nitrogen protection in the four-necked reaction flask. 126.2g (2.1mol) of anhydrous isopropanol, 222.6g (2.2mol) of anhydrous Et3N and 2400g of petroleum ether at 40-60°C were placed at the bottom of the reaction bottle and heated to 25°C.

[0058] 2) Reaction

[0059] 118g (1.0mol) of 99% MePCl2 was diluted with 300g of petroleum ether at 40-60°C, and was added dropwise into the reaction bottle under vigorous stirring. The dropwise addition process was 2 hours, during which the temperature in the bottle was maintained at 25±2°C. After the dropwise addition, keep stirring at 25±2°C for 1 hour. Cool to 15 ° C, ready to drop lye.

[0060] 3) neutralize

[0061] 2.1 mol of 20% by weight NaOH aqueous solution was stirred and dropped into the cooling water outside the reaction flask to maintain the temperature inside the flask at 15±2°C. After dripping the NaOH solution, stir vigorously for 5 minutes...

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PUM

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Abstract

The invention relates to a preparation method of dialkyl methylphosphonite. tertiary amine with pKa greater than 10 is adopted as the acid binding agent, methyl phosphonic dichloride and alcohol react in a solvent, and the mole ratio of the methyl phosphonic dichloride, alcohol and tertiary amine is 1:2.0-2.4:2.0-2.4, the produced tertiary amine hydrochloride is neutralized with a caustic soda aqueous solution, and the solvent and tertiary amine obtained by evaporation is recycled and reused. The alkyl of the dialkyl methylphosphonite is straight chain and side chain alkane or alkene of aliphatic C1-C4, the alcohol refers to methanol, ethanol, propanol, isopropanol, allyl alcohol, n-butanol, isobutanol and the like, the tertiary amine refers to tertiary fatty amine, and also refers to fatty group and aromatic mixed tertiary amine, at the same time, the pKa of the tertiary amine is required to be greater than 10, and the tertiary amine can include triethylamine, tripropylamine and tributylamine.

Description

technical field [0001] The invention relates to a method for preparing dialkyl methylphosphonite, which belongs to the technical field of metal organic compound preparation. Background technique [0002] Dialkyl methylphosphonite is an O,O-dialkylmethylphosphonite containing a phosphorus-carbon bond and is widely used in the preparation of flame retardants and herbicides. [0003] DE 3,911,230 (Hoechst 1989) discloses that diethoxyphosphorous chloride is reacted with methylmagnesium halide in solvent tetrahydrofuran to obtain diethyl methylphosphonite through Grignard reaction, [0004] (EtO)2PCl+MeMgBr→MeP(OEt)2+MgBr+MgCl yield 87.1%. [0005] The more method is that MePCl2 (methyl phosphine dichloride) reacts with alcohol, and the hydrogen chloride produced is neutralized with an acid-binding agent. [0006] MePCl2+2HOEt→MeP(OEt)2+2HCl [0007] USP2,903,475 (Virginia Carolina Chem.Corp.1955) MePCl and pentane mixed solution are added dropwise in ethanol and pentane mixe...

Claims

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Application Information

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IPC IPC(8): C07F9/48
CPCC07F9/4816C07F9/4866
Inventor 庄建元
Owner 庄建元
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