Preparation method of L-octohydroindoline-2-formic acid

A technology of indoline and formic acid, which is applied in the field of preparation of L-octahydroindoline-2-carboxylic acid, can solve the problems of high raw material prices and no market advantages, and achieve low cost, environmentally friendly process, and clean hydrogenation route Effect

Inactive Publication Date: 2010-09-08
安徽世华化工有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, a large amount of waste water will be generated during the synthesis pro

Method used

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  • Preparation method of L-octohydroindoline-2-formic acid
  • Preparation method of L-octohydroindoline-2-formic acid
  • Preparation method of L-octohydroindoline-2-formic acid

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Embodiment Construction

[0006] The preparation method of L-octahydroindoline-2-carboxylic acid:

[0007] (1), the condensation process synthesizes o-nitropyruvate:

[0008] The reaction formula is as follows:

[0009]

[0010] C 2 h 5 Na+HCl→C 2 h 5 OH+NaCl

[0011] Add 185 kilograms of diethyl oxalate, 121 kilograms of o-nitrotoluene and 87 kilograms of sodium ethylate to the reaction kettle, add 2000 l of heat to reflux for 3 hours, evaporate the ethanol, add water to the reaction kettle, stir for deep decomposition, and then steam Remove o-nitrotoluene until the reaction solution is clear, adjust the pH to 0.5 with 30% hydrochloric acid after reaching room temperature, spin dry by centrifugation to obtain a solid, and dry it at 60-70°C.

[0012] (2), hydrogenation section prepares indole-2-carboxylic acid:

[0013] The reaction formula is as follows:

[0014]

[0015] Add 81kg of o-nitropyruvate and 600l of 95% ethanol to the reaction kettle, adjust the pH to 7-8 with 30% lye, add ni...

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Abstract

The invention discloses a preparation method of L-octohydroindoline-2-formic acid. The method comprises the following steps of: preparing indole-2-formic acid through condensation and hydrogenation by using diethyl oxalate and ortho-nitrotoluene as raw materials; adding acetic anhydride and hydrochloric acid by using the indole-2-formic acid as a raw material to carry out acylation and hydrogenation working procedures to obtain a (R, S) indoline-2-formic acid mixture; splitting the (R, S) indoline-2-formic acid mixture to obtain R indoline-2-formic acid; treating the R indoline-2-formic acid, water and hydrochloric acid through racemizing, cooling, regulating the pH value, centrifuging and drying to obtain S indoline-2-formic acid; and reacting the S indoline-2-formic acid, methanol and a catalyst to obtain the L-octohydroindoline-2-formic acid. The invention has the advantages of low cost, clean and environmentally-friendly hydrogenation route, less generated waste water and high yield of the final finished product L-octohydroindoline-2-formic acid.

Description

technical field [0001] The invention relates to the field of chemical synthesis, in particular to a preparation method of L-octahydroindoline-2-carboxylic acid. Background technique [0002] Indole and its homologs can be synthesized by a variety of methods, among which the Fischer synthesis method is the most common, which uses phenylhydrazone to heat rearrangement under acid catalysis to eliminate a molecule of ammonia to obtain 2-substituted or 3-substituted indole derivatives . Commonly used aldehydes or ketones and other substances such as phenylhydrazine are heated and refluxed in acetic acid to obtain phenylhydrazone, and phenylhydrazone is immediately rearranged under acid catalysis without separation to eliminate ammonia to obtain indole ring compounds. However, a large amount of waste water will be generated during the synthesis process, and the price of raw materials used is high, so there is no market advantage. Contents of the invention [0003] The inventio...

Claims

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Application Information

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IPC IPC(8): C07D209/42
Inventor 孔祥俊蔡芝秀孔令翔孔德明薛晓寅顾国政范一峰
Owner 安徽世华化工有限公司
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