Method for synthesizing 5,6,7,8-tetrahydroquinoline

A technology of tetrahydroquinoline and synthetic method, which is applied in the field of key intermediates of cefquinidine, can solve the problems of high equipment requirements, low yield, large pollution, etc., and achieve low reaction temperature, high yield, and low material loss. The effect of energy consumption reduction

Active Publication Date: 2009-09-30
GREAT FOREST BIOMEDICAL LTD
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  • Abstract
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Problems solved by technology

[0010] In order to solve the problems of high equipment requirements, heavy pollution, and low yield in th

Method used

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  • Method for synthesizing 5,6,7,8-tetrahydroquinoline
  • Method for synthesizing 5,6,7,8-tetrahydroquinoline
  • Method for synthesizing 5,6,7,8-tetrahydroquinoline

Examples

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Embodiment 1

[0027] Embodiment 1: with CuCl 2 Preparation of PD catalyst

[0028] Add 20g of palladium carbon (5wt% palladium loading) purchased from Zhejiang Metallurgical Research Institute Co., Ltd. to 100mL CuCl 2 (2mol / L) aqueous solution, stir and heat to about 50°C, then add 400mL NaHCO 3 Solution (1mol / L), continued to stir for 2 hours, filtered, and the filter cake was washed with 2×20mL water, and vacuum-dried at 130°C to obtain 32.4g of catalyst, which was designated as PD-1.

Embodiment 2

[0029] Embodiment 2: with ZnCl 2 Preparation of PD catalyst

[0030] Add 10g of palladium carbon (5%) purchased from Zhejiang Metallurgical Research Institute Co., Ltd. to 50mLZnCl 2 (1mol / L) aqueous solution, under stirring, add 200mL NaHCO at about 10°C 3 Solution (0.5mol / L), continued to stir for 3 hours, filtered, and the filter cake was washed with 2×20mL water, and vacuum-dried at 120°C to obtain 13.2g of catalyst, which was designated as PD-2.

Embodiment 3

[0031] Embodiment 3: with FeCl 2 Preparation of PD catalyst

[0032] Add 10g of palladium carbon (5%) purchased from Zhejiang Metallurgical Research Institute Co., Ltd. to 40mLFeCl 2 (5mol / L) aqueous solution, stir and heat to about 30°C, add 210mL NaHCO 3 Solution (1.9mol / L), continued to stir for 2 hours, filtered, and the filter cake was washed with 2×20mL water, and vacuum-dried at 100°C to obtain 22.5g of catalyst, which was designated as PD-3.

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Abstract

The invention discloses a method for synthesizing 5,6,7,8-tetrahydroquinoline represented by a formula (I), which comprises the following steps: using quinoline represented by a formula (II) as a raw material and using PD as a catalyst, performing a catalytic hydrogenation reaction at a temperature of between 20 and 110 DEG C till the pressure of hydrogen is constant; emptying the hydrogen till the pressure is 2 atmospheres; stirring and raising temperature to between 140 and 300 DEG C to perform an isomerization reaction for 1 to 4 hours; and performing post treatment of reaction products after the reaction is finished to obtain the 5,6,7,8-tetrahydroquinoline. The method for preparing the PD catalyst comprises the following steps: adding a palladium-carbon catalyst with a palladium loading capacity of 5 weight percent into an aqueous of a hydrochloride, stirring the solution and heating the solution to between 10 and 50 DEG C, and adding a supercarbonate solution in the same amount into the solution; stirring the mixed solution for 1 to 4 hours; filtering the mixed solution; washing a filter cake; and drying the filter cake to obtain the PD catalyst. The method adopts the self-prepared PD catalyst with special selectivity, so the hydrogenation reaction and the isomerization reaction are continuative, the reaction temperature is reduced greatly, the material loss and energy consumption are reduced and the yield is improved greatly.

Description

(1) Technical field [0001] The invention relates to a synthetic method of 5,6,7,8-tetrahydroquinoline (ie 2,3-cyclohexenopyridine), a key intermediate of cefquinidine. (2) Background technology [0002] In the prior art, the synthetic method of 5,6,7,8-tetrahydroquinoline mainly contains following two kinds: [0003] 1. Quinoline hydrogenation method [0004] Vierhapper (J.C.S Perkin I, 1980, 1933) reported the hydrogenation of quinoline with a platinum catalyst in trifluoroacetic acid at a pressure of 50 p.s.i, with a yield of 84%. Although the yield of this method is high, the reaction under strong acid conditions requires high requirements for reaction equipment, which is difficult to achieve industrially. [0005] In addition, there is a Japanese patent JP6157461 method, under the catalysis of nickel-chromium-copper catalyst, quinoline is hydrogenated at 140 ° C to generate 1,2,3,4-tetrahydroquinoline, the catalyst is recovered by filtration, and then catalyzed by pall...

Claims

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Application Information

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IPC IPC(8): C07D215/06B01J23/44
Inventor 顾海宁李小玲张习坤
Owner GREAT FOREST BIOMEDICAL LTD
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