Chemical synthesis process for iminostilbene

Abstract

The invention provides a method for chemically synthesizing iminostilbene which is shown as a formula (I), comprising the following steps that: catalyst is filled on a fixed catalyst bed, the temperature of the catalyst bed is increased to between 400 and 600 DEG C by heating the catalyst bed electrically, iminodibenzyl which is shown as a formula (II) and is pre-heated to be liquated is sent to the fixed catalyst bed through high-pressure water vapour, the flow rate of the water vapour is controlled to between 0.2 and 20l / h by the iminodibenzyl fluid volume, and the material which passes through the fixed catalyst bed is put into a receiving device holding cooling water to produce the mixed fluid which is subject to moisture evaporation to dryness is crystallized again so that the iminostilbene is obtained. The method mainly has the advantages of high reaction yield coefficient up to 93.8 percent, low production, advanced process flow and convenient operation.

Description

(1) Technical field [0001] The invention relates to a chemical synthesis method of a pharmaceutical intermediate iminostilbene. (2) Background technology [0002] Iminostilbene is a key intermediate in the synthesis of carbamazepine. Carbamazepine is mainly used for the treatment of all types of epilepsy except absence seizures, the treatment of trigeminal neuralgia and the prevention of manic depression. [0003] Before the present invention was made, in the chemical synthesis method of iminostilbene in the prior art, a kind of technique is to adopt the method preparation of bromination, dehydrobromination; Another kind of technique is to adopt the technology of catalytic dehydrogenation, as disclosed in EP570336 A kind of iminodibenzyl is used as raw material, and iminostilbene is prepared by catalytic dehydrogenation under the action of oxides containing Fe, K, Cr, etc.; EP0237952 discloses a kind of iminodibenzyl as raw material, in Pt / C or Pd / C or Fe 2 o 3 Under ca...

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Problems solved by technology

[0003] Before the present invention was made, in the chemical synthesis method of iminostilbene in the prior art, a kind of technique is to adopt the method preparation of bromination, dehydrobromination; Another kind of technique is to adopt the technology of catalytic dehydrogenation, as disclosed in EP570336 A kind of using iminodibenzyl as raw material, under the action of oxides containing Fe, K, Cr etc. catalytic dehydrogenation makes iminostilbene; EP0237952 discloses a kind of using iminodibenzyl as raw material, in Pt / C or Pd / C or Fe 2 o 3 Under catalysis, take o-nitrotoluene or dimethyl maleate as hydrogen acceptor, and react in xylene amine or xylene ether solvent to prepare iminostilbene; in these processes, the first process is due to the use of bromine As a bromination reagent, there are many by-products and low product yield; the catalyst used in the second process is generally more expensive, and the organic solvent used is more toxic or dangerous, and the product quality is poor.

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