One-pot method for preparing O-alkyl hydroxylamine hydrochloride and N,O-dialkyl hydroxylamine hydrochloride

A technology of dialkylhydroxylamine hydrochloride and alkylhydroxylamine hydrochloride, which is applied in the field of preparing O-alkylhydroxylamine hydrochloride and N in one pot, can solve problems such as difficult industrialization, and achieve small molecular weight and few impurities , good water solubility

Inactive Publication Date: 2020-10-09
和德化学(苏州)有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

are difficult to industrialize

Method used

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  • One-pot method for preparing O-alkyl hydroxylamine hydrochloride and N,O-dialkyl hydroxylamine hydrochloride
  • One-pot method for preparing O-alkyl hydroxylamine hydrochloride and N,O-dialkyl hydroxylamine hydrochloride

Examples

Experimental program
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Effect test

Embodiment 1

[0032] Embodiment 1: the preparation of N, O-dimethylhydroxylamine hydrochloride

[0033]First mix 35.0g of hydroxylamine hydrochloride with 36.0g of water and 37.0g of methyl acetate, stir at 25°C, add dropwise 113.3g of 30% sodium hydroxide solution, add dropwise for 2 hours, and react for 1 hour. Add 160.0g dimethyl sulfate dropwise to the reaction kettle, and add dropwise 104.3g 50% sodium hydroxide solution at the same time. After passing the reaction for 5 hours, add 49g concentrated sulfuric acid dropwise and heat up to 76°C for hydrolysis for 5 hours. After passing the test, slowly Add 80 g of 50% liquid caustic soda to adjust the pH to 12, steam N, O-dimethylhydroxylamine under normal pressure, and collect fractions from 43 to 70°C. Acidify with hydrochloric acid gas, cool to crystallize, filter, wash twice with 20ml of cold ethanol, and dry to obtain 37.1g of N,O-dimethylhydroxylamine hydrochloride, yield 76.1%, white crystal, melting point 113.2-114.4°C, infrared T...

Embodiment 2

[0034] Embodiment 2: the preparation of N, O-diethylhydroxylamine hydrochloride

[0035] First mix 70.0g of hydroxylamine hydrochloride with 72.0g of water and 80.0g of methyl acetate, stir at 30°C, add dropwise 240.0g of 30% sodium hydroxide solution, add dropwise for 1 hour, and react for 3 hours. Add 323.4g of diethyl sulfate dropwise to the kettle, and add dropwise 200.5g of 50% sodium hydroxide solution at the same time. After the dropwise addition time is 2 hours, after the reaction is qualified, add 98.0g of concentrated sulfuric acid dropwise and raise the temperature to 80°C for 3 hours for hydrolysis, and the test is qualified Then slowly add 87.0 g of caustic soda to adjust the pH to 12, steam N, O-diethylhydroxylamine under normal pressure, and collect fractions from 60 to 90°C. Acidify with hydrochloric acid gas, cool and crystallize, filter and dry to obtain 98.2 g of N, O-diethylhydroxylamine hydrochloride, yield 78.2%, white crystal, melting point 123.4-125.2 °...

Embodiment 3

[0036] Embodiment 3: the preparation of N, O-dipropyl hydroxylamine hydrochloride

[0037] First mix 700.0g of hydroxylamine hydrochloride with 800.0g of water and 810.0g of methyl acetate, stir at 20°C, add 2200.0g of 40% sodium hydroxide solution dropwise, add dropwise for 2.3 hours, and react for 1.5 hours. Add 3075g, 1-bromopropane, add 400.0g sodium hydroxide flake alkali at the same time, reflux reaction for 8 hours, after passing the test, cool down, add 980.0g concentrated sulfuric acid dropwise and heat up to 60°C for hydrolysis for 7 hours, slowly add 1200.0 Adjust the pH to 12 with g caustic soda, steam N, O-dipropylhydroxylamine under atmospheric pressure, and collect fractions from 60 to 99°C. Acidify with hydrochloric acid gas, cool and crystallize, filter and dry to obtain 1246.5 g of N, O-dipropylhydroxylamine hydrochloride, yield 81.1%, white crystal, melting point 146.2-148.1 ° C, infrared spectrum consistent with the standard spectrum, water content 0.48 %,...

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Abstract

The invention relates to the field of organic synthesis, in particular to a one-pot method for preparing O-alkyl hydroxylamine hydrochloride and N,O-dialkyl hydroxylamine hydrochloride. The method comprises the following steps: S1, acetylation: mixing hydroxylamine hydrochloride with water and methyl acetate, and dropwise adding a sodium hydroxide solution while stirring at room temperature to obtain an intermediate acetyl hydroxylamine; S2, alkylation: dropwise adding an alkylation reagent into the reaction kettle at normal temperature, and then heating the reactants for reaction; S3, hydrolysis and purification: after the reaction is qualified, adding concentrated sulfuric acid, performing heating hydrolysis, after the reaction is qualified, adding caustic soda flakes or liquid caustic soda to adjust the pH value to 12, carrying out atmospheric distillation and hydrochloric acid acidification, cooling the product for crystallization, and centrifuging and drying the crystal to obtaina final product. According to the invention, methyl acetate is used as an acetyl protective agent, and compared with ethyl acetate, methyl acetate has the advantages of good water solubility, small reaction steric hindrance, sufficient protection, few impurities, low price and cost and the like; therefore, the method has the advantages of high product purity, simple process operation, accessible raw materials, simple wastewater components and environment friendliness, and is suitable for industrial production.

Description

technical field [0001] The invention relates to the field of organic synthesis, in particular to a method for preparing O-alkyl hydroxylamine hydrochloride and N, O-dialkyl hydroxylamine hydrochloride in one pot. Background technique [0002] O-alkoxyamine hydrochloride series compounds are mainly used in the synthesis of alkoxyamination reagents to form oximes with ketones. It is widely used in medicine and pesticides: such as pesticide benzotrione, clethodim, ethenoxydim, etc.; in medicine, it is mainly used for cefuroxime sodium, cefuroxime axetil, etc.; fungicide phenoxystrobin, etc. At the same time, it can also be used as an intermediate of functional dyes. N, O-dialkyl hydroxylamine hydrochloride is mainly used in the synthesis of pharmaceuticals, pesticides and optical material compounds, among which N, O-dimethyl hydroxylamine hydrochloride is used to prepare Weinreb amide. [0003] O-alkyl hydroxylamine hydrochloride is the most widely used and researched. At pre...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C239/20
CPCC07C239/20C07C259/06
Inventor 施波杨学波卞小豹徐开亮
Owner 和德化学(苏州)有限公司
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