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Preparation method of benzo[d]oxazole derivative

A derivative, oxazole technology, applied in the field of new preparation of pharmaceutical intermediates, can solve problems such as synthesis difficulties

Inactive Publication Date: 2017-04-26
长沙深橙生物科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The synthesis of 2-chlorobenzo[d]oxazole-5-carboxamide is difficult at present

Method used

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  • Preparation method of benzo[d]oxazole derivative
  • Preparation method of benzo[d]oxazole derivative
  • Preparation method of benzo[d]oxazole derivative

Examples

Experimental program
Comparison scheme
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Embodiment 1

[0022] (1) Synthesis of 3-amino-4-hydroxybenzonitrile

[0023] Add 15g of 2-nitro-4-cyanophenol and 1g of 10% palladium carbon to 120ml of methanol, feed hydrogen, stir at room temperature for 8 hours, filter, collect the filtrate, and concentrate to obtain 13g of 3-amino-4-hydroxybenzyl Nitrile.

[0024] (2) Synthesis of 5-cyanobenzo[d]oxazole-2-(3H)-thilone

[0025] Add 12g of 3-amino-4-hydroxybenzonitrile and 18g of potassium ethyl xanthate to 180ml of pyridine, heat to reflux and stir for 3 hours, cool to room temperature, add 10% hydrochloric acid, then add ethyl acetate, extract and separate the liquid, The organic phase was collected, dried and concentrated, and the residue was separated on a silica gel column to obtain 9 g of 5-cyanobenzo[d]oxazole-2-(3H)-thianone.

[0026] (3) Synthesis of 2-chloro-5-cyanobenzo[d]oxazole

[0027] Add 8g of 5-cyanobenzo[d]oxazole-2-(3H)-thione to 70ml of thionyl chloride, heat to reflux and stir for 22 hours, cool and concentrate to...

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Abstract

The invention discloses a preparation method of a benzo[d]oxazole derivative, namely 2-chlorobenzo[d]oxazole-5-formamide. With 2-nitro-4-cyanophenol being an initial raw material, the target product is obtained through reducing, ring closure, chlorinating and hydrolyzing, and the compound is an important medical intermediate.

Description

technical field [0001] The invention relates to a novel preparation method of a pharmaceutical intermediate, in particular to a preparation method of benzo[d]oxazole derivative 2-chlorobenzo[d]oxazole-5-carboxamide. [0002] technical background [0003] Compound 2-chlorobenzo[d]oxazole-5-carboxamide, the structural formula is: [0004] [0005] The compound 2-chlorobenzo[d]oxazole-5-carboxamide and related derivatives are widely used in medicinal chemistry and organic synthesis. Currently, the synthesis of 2-chlorobenzo[d]oxazole-5-carboxamide is difficult. Therefore, it is necessary to develop a synthetic method with easy-to-obtain raw materials, convenient operation, easy-to-control reaction and suitable overall yield. Contents of the invention [0006] The invention discloses a method for preparing 2-chlorobenzo[d]oxazole-5-carboxamide, which uses 2-nitro-4-cyanophenol as a starting material and undergoes reduction, ring closure, chlorination, The target product 5...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D263/58
CPCC07D263/58
Inventor 不公告发明人
Owner 长沙深橙生物科技有限公司