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Preparation method of 8-amino-2-(1H-tetrazol-5-yl)-chromen hydrochloride

A technology of benzopyrone hydrochloride and hydroxyacetophenone, applied in the field of medicine and chemical industry, can solve the problems of difficult realization of industrialized production, harsh reaction conditions and the like

Inactive Publication Date: 2012-02-22
中国中化股份有限公司 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Dangerous reagents such as n-butyllithium are used in this route, and the reaction conditions are relatively harsh. It needs to be carried out at -78°C, and industrial production is difficult to achieve.

Method used

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  • Preparation method of 8-amino-2-(1H-tetrazol-5-yl)-chromen hydrochloride
  • Preparation method of 8-amino-2-(1H-tetrazol-5-yl)-chromen hydrochloride
  • Preparation method of 8-amino-2-(1H-tetrazol-5-yl)-chromen hydrochloride

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Embodiment 1

[0026] (1) Synthesis of N-(3-acetyl-2-hydroxyl-phenyl)-acetamide (III)

[0027] Install a thermometer and a mechanical stirrer on a 500ml four-neck flask, and connect a tail gas absorption device. Then, 30.2 g (0.2 mol) of 3-amino-2-hydroxyacetophenone (II), 240 ml of ethyl acetate, 30 g of 20% aqueous sodium hydroxide solution and 16 g (0.2 mol) of pyridine were added to the flask. Stirring was started, and the reaction temperature was controlled at 0-5°C, and 16 g (0.2 mol) of acetyl chloride was added dropwise, and the addition was completed within 0.5 h. The reaction was incubated for 1 h, and samples were taken for liquid chromatography analysis to determine the end point of the reaction. Warm up to 20-30°C, add 10ml of water and 12.5ml of concentrated hydrochloric acid (analytical pure), and continue stirring for 0.5h. The sodium hydroxide aqueous solution is used to neutralize the hydrochloride, and water and concentrated hydrochloric acid are added to wash the reacti...

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Abstract

The invention discloses a preparation method of 8-amino-2-(1H-tetrazol-5-yl)-chromen hydrochloride. The method comprises the steps of: (1) preparing a compound (III) N-(3-acetyl-2-hydroxyl-phenyl)-acetamide: adding a compound (II) 3-amino-2-hydroxyacetophenone, a solvent, a sodium hydroxide or potassium hydroxide aqueous solution and an acid binding agent into a reaction container for uniform mixing, and adding acetyl chloride dropwisely at a temperature of 0-5DEG C, then keeping the temperature at 1-5DEG C for reaction till the end; (2) preparing an end product: adding sodium methoxide or potassium tert-butoxide, DMSO (dimethylsulfoxide) into a reaction container and stirring them well, and adding the compound (III) and a compound (IV) 1H-tetrazol-5-carboxylic acid ethyl ester in order, then leaving the mixture to react at a temperature of 80-85DEG C till the end. The method of the invention has easily available raw materials and high added value, and can obtain high value-added products. In spite of multi-step reactions, the reactions can be completed in one or two steps. Therefore, the method has an obviously simplified process, and boasts industrial production value.

Description

technical field [0001] The invention belongs to the field of medicine and chemical industry, and specifically relates to a method for preparing 8-amino-2-(1H-5-tetrazole)-4-benzopyrone hydrochloride. Background technique [0002] 8-Amino-2-(1H-5-tetrazole)-4-benzopyrone hydrochloride, referred to as AOTH, English name: 8-amino-2-(1H-tetrazol-5-yl)-chromen Hydrochloride, CAS No: 110683-23-3, molecular weight: 265.66, appearance: yellow powder. The structural formula is: [0003] [0004] AOTH is the main intermediate of Pranlukast. Pranlukast is a drug for the treatment of bronchial asthma, its chemical name is: 4-oxo-8-(4-(4-phenylbutoxy)benzamido)-2-(tetrazol-5-yl) -4H-1-benzopyran, molecular formula: C 27 h 23 N 5 o 4 , molecular weight: 481.5026, CAS No.103177-37-3, structural formula: [0005] [0006] Patent WO9532199 discloses that 2-hydroxy-3-amino-acetophenone is used as the starting material to condense with tetrazolate under the action of hexamethyldi...

Claims

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Application Information

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IPC IPC(8): C07D405/04
Inventor 徐宇伦白振林安劲松陈建春吉锦秀
Owner 中国中化股份有限公司
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