Preparation method of 4-amino-1, 3-dihydro-benzimidazole-2-one

Abstract

The invention provides a preparation method of 4-amino-1, 3-dihydro-benzimidazole-2-one, which comprises the following steps: Q1, preparation of 2, 6-dinitrochlorobenzene, Q2, preparation of 2, 6-dinitroaniline, Q3, preparation of 3-nitro-o-phenylenediamine, Q4, preparation of 4-nitro-1H-benzo[d]imidazole-2(3H)-one and Q5, preparation of 4-amino-1, 3-dihydro-benzimidazole-2-one. According to the preparation method, 3, 5-dinitro-4-chlorobenzoic acid which is low in price is used as a raw material, and the high-yield 4-amino-1, 3-dihydro-benzimidazole-2-one is obtained through reactions such asdecarboxylation and ammoniation. The whole reaction process is easy to control, the product yield is high, good social benefits and economic benefits can be brought, and the economic value potential is large.

Description

technical field [0001] The present invention relates to the technical field of organic compound synthesis and pharmacy, and more specifically, relates to a preparation method of 4-amino-1,3-dihydro-benzimidazol-2-one. Background technique [0002] Transient receptor potential vanilloid type 1 (transient receptor potential vanilloid type 1, TRPV1) is a non-selective cation channel, mainly expressed in sensory neurons and their fibers, such as dorsal root ganglion and trigeminal ganglion, and participates in In a variety of physiological and pathological processes, TRPV1 is involved in the regulation of body temperature, mainly by regulating the temperature sensing area of ​​the brain; TRPV1 is also involved in the treatment of certain central nervous system diseases. Regulating the activity of TRPV1 can effectively control the excitability of neurons; TRPV1 has been proved to be the main sensor in the pain channel, and the pain involving TRPV1 includes inflammation-related pa...

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Problems solved by technology

[0003] At present, TRPV1 agonists are mainly used for pain treatment. Its mechanism of action is to activate TRPV1 channels, influx calcium ions, and excite primary sensory neurons. Long-term use leads to desensitization of neurons, thereby blocking the transmission of pain sensation. However, this analgesic mechanism has relatively large side effects. For example, after capsaicin is combined with TRPV1, a large amount of calcium ions in nerve cells will accumulate, the cell membrane will be destroyed, the intracellular capacitance will be greatly reduced, and the mitochondrial membrane permeability may also be changed, eventually leading to neuronal apoptosis

[0004] Since TRPV1 inhibitors have the effect of blocking pain sensation without causing damage to nerve cells and have extremely low side effects, more and more attention has been paid to the research on TRPV1 inhibitors. 4-Amino-1,3-dihydro-benzo Imidazol-2-one is an important intermediate for the preparation of TRPV1 inhibitors, but in the prior art, the preparation method of 4-amino-1,3-dihydro-benzimidazol-2-one has a slow reaction process and low final yield. Not suitable for industrial production

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