Preparation method of caffeine intermediate N,N-1,3-dimethyl-4,5-diamido urazine

A technology of dimethyl and intermediates, which is applied in the field of synthesis and preparation of organic compounds, and can solve the problems of low yield of dimethyl DAU, poor selectivity and unfavorable Raney nickel catalysts, etc.

Active Publication Date: 2014-08-27
CSPC INNOVATION PHARMA
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Based on the above-mentioned distinguishing technical features, the technical problem solved by the Chinese patent document CN1017241B is to overcome the instability of dimethyl DAU caused by the use of alkaline solution in the British patent document GB2001310. However, the Chinese patent document CN1017241B records the use of neutral The water is used as the reaction medium, and the dimethyl DAU is formylated with formic acid immediately after the reaction. The additional step of the formic acid formylation of the dimethyl DAU is because the dimethyl DAU is still unstable and is stabilized by formic acid formylation. form, or just to prepare the target product, the Chinese patent literature does not indicate, and there is no corresponding record in its examp

Method used

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  • Preparation method of caffeine intermediate N,N-1,3-dimethyl-4,5-diamido urazine
  • Preparation method of caffeine intermediate N,N-1,3-dimethyl-4,5-diamido urazine
  • Preparation method of caffeine intermediate N,N-1,3-dimethyl-4,5-diamido urazine

Examples

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Embodiment 1

[0021] Example 1 Preparation of caffeine intermediate N,N-1,3-dimethyl-4,5-disemicarbazine according to the present invention

[0022] Weigh 200g of dimethyl NAU dry product, 2400ml of water, 24g of Raney nickel, solid Na 2 CO 3 6g, NaCl1.92g, put into the hydrogenation reduction kettle for replacement, heat the reaction kettle, and start the reaction at 55°C, H 2 The pressure is 0.40MPa, the reaction time is 50min, the yield of dimethyl DAU is 94.5%, and the purity is 95.3%.

Embodiment 2

[0023] Example 2 Preparation of caffeine intermediate N,N-1,3-dimethyl-4,5-disemicarbazine according to the present invention

[0024] Weigh 200g of dimethyl NAU dry product, 2400ml of water, 25g of Raney nickel, solid Na 2 CO 3 10g, NaBr2g, put into the hydrogenation reduction kettle for replacement, heat the reaction kettle, start the reaction at 55°C, H 2 The pressure is 0.35MPa, the reaction time is 40min, the yield of dimethyl DAU is 93.2%, and the purity is 93.4%.

Embodiment 3

[0025] Example 3 Preparation of caffeine intermediate N,N-1,3-dimethyl-4,5-disemicarbazine according to the present invention

[0026] Weigh 200g of dimethyl NAU dry product, 3000ml of water, 15g of Raney nickel, solid NaHCO 3 35g, KI0.8g, put into the hydrogenation reduction kettle for replacement, heat the reaction kettle, start reaction at 30°C, H 2 The pressure is 0.60MPa, the reaction time is 100min, the yield of dimethyl DAU is 90.9%, and the purity is 92.5%.

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Abstract

The invention relates to a preparation method of the caffeine intermediate N,N-1,3-dimethyl-4,5-diamido urazine and belongs to the technical field of synthesis and preparation of organic compounds. According to the preparation method, a hydrogen addition reaction is carried out under heated and pressurized conditions with N,N-1,3-dimethyl-4-imido-5-isonitroso urazine as the starting material and raney nickel as the catalyst, an aqueous solution containing metal halide and alkaline substances is used as the reaction medium, the preparation method has the advantages of being smooth and controllable in reaction, high in catalytic activity and stable in quality of dimethyl-DAU, and the yield and the quality of the dimethyl-DAU are improved.

Description

technical field [0001] The invention relates to a preparation method of a caffeine intermediate, in particular to a preparation method of a caffeine intermediate N,N-1,3-dimethyl-4,5-diaminocarbazine, and belongs to the technical field of synthesis and preparation of organic compounds . Background technique [0002] Caffeine, a xanthine drug, has excitatory and diuretic effects on the heart and brain nerves, and is widely used clinically. N,N-1,3-Dimethyl-4,5-diaminocarbazine (dimethyl-DAU) is an important intermediate in the synthesis of caffeine. At present, it is composed of N,N-1,3- Dimethyl-4-imino-5-isonitrosourazine (dimethyl-NAU) is obtained through reduction reaction. Among them, the reduction reaction methods mainly include iron powder plus sodium chloride reduction, catalytic hydrogenation reduction and electrochemical reduction. The iron powder reduction reaction will produce a large amount of iron sludge, which will have a bad impact on the environment; elect...

Claims

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Application Information

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IPC IPC(8): C07D239/22
CPCC07D239/22
Inventor 刘晖田玉妙谢丽莎张浩韩志杰
Owner CSPC INNOVATION PHARMA
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