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Preparation method of tert-butyl carbazate

A technology of carbazic acid and tert-butyl ester, which is applied in the field of one-pot preparation of tert-butyl carbazate, which can solve the problems of long reaction time, difficulty in industrialization, and expensive medicines, and achieve simple process and easy operation , the effect of little environmental pollution

Active Publication Date: 2013-02-06
苏州卫优知识产权运营有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In 1959, Louis A. Carpino synthesized tert-butyl carbazate for the first time by using sodium tert-butoxide, carbon sulfide, methyl iodide, etc., and applied it to the protection process of amino groups. However, in this synthesis process, the drug price is expensive and the reaction time Too long and other conditions require that only small batches of products can be prepared, and it is difficult to realize industrialization

Method used

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Examples

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Embodiment 1

[0023] 15.7 grams (0.1 moles) of phenyl chloroformate, 8 grams (0.1 moles) of tert-butanol, 1.5 grams of solid base catalyst prepared by the method of Example 1 and 1-methyl-3-butylimidazolium tetrafluoroborate ion Add 3 grams of liquid into the reactor, and after esterification at 30°C for 6 hours, add 64 grams (0.1 mole) of hydrazine hydrate aqueous solution with a mass concentration of 50% (0.1 mole) for 3 hours of replacement reaction at 60°C. After the reaction, cool the reaction solution to At room temperature (25°C), add ethyl acetate (3×50ml) for extraction (i.e. extract 3 times, 50mL each time, the same below), take the extract and concentrate under reduced pressure until no liquid flows out to remove the extractant, and the obtained concentrate Carry out silica gel column chromatography (petroleum ether: ethyl acetate = 5:1 (volume ratio)), TLC follow-up detection, collect the eluate containing the target component, and concentrate to dryness under reduced pressure to...

Embodiment 2

[0025]15.7 grams (0.1 moles) of phenyl chloroformate, 24 grams (0.3 moles) of tert-butanol, 3 grams of solid base catalyst prepared by the method in Example 1 and 1-methyl-3-butylimidazole hexafluorophosphate ionic liquid Add 2.5 grams into the reactor, and after esterification at 30°C for 1 hour, add 96 grams (0.15 moles) of hydrazine hydrate aqueous solution with a mass concentration of 50% (0.15 moles) for 1 hour of substitution reaction at 60°C. After the reaction, cool the reaction solution to At room temperature (25°C), add ethyl acetate (3×50ml) for extraction (i.e. extract 3 times, 50mL each time, the same below), take the extract and concentrate under reduced pressure until no liquid flows out to remove the extractant, and the obtained concentrate Carry out silica gel column chromatography (petroleum ether: ethyl acetate = 5:1 (volume ratio)), TLC follow-up detection, collect the eluate containing the target component, and concentrate to dryness under reduced pressure ...

Embodiment 3

[0027] 15.7 grams (0.1 moles) of phenyl chloroformate, 5 grams (0.3 moles) of tert-butanol, 5 grams of solid base catalyst prepared by the method in Example 1 and 1-methyl-3-octylimidazolium tetrafluoroborate ion Add 4 grams of liquid into the reactor, and after esterification reaction at 40°C for 1 hour, add 128 grams (0.2 moles) of hydrazine hydrate aqueous solution with a mass concentration of 50% (0.2 moles) to replace and react at 75°C for 5 hours. After the reaction, cool the reaction liquid to room temperature (25°C), add ethyl acetate (3×50ml) for extraction (i.e. extract 3 times, 50mL each time, the same below), take the extract and concentrate under reduced pressure until no liquid flows out to remove the extractant, and the obtained concentrated The liquid was subjected to silica gel column chromatography (petroleum ether: ethyl acetate = 5:1 (volume ratio)), followed by TLC detection, and the eluate containing the target component was collected and concentrated to d...

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Abstract

The invention discloses a preparation method of tert-butyl carbazate. The method includes: using phenyl chloroformate and tert-butanol as raw materials, performing esterification in ionic liquid at the temperature of 30-40 DEG C under the action of solid base catalysts, adding hydrazine hydrate into esterification liquid after esterification is completed, performing substitution reaction at the temperature of 60-75 DEG C, and subjecting the reaction liquid to separation and purification after the substitution reaction is finished so that the tert-butyl carbazate is obtained. The preparation method is simple in process, high in yield, easy to operate, free of phosphine ligands and less in environmental pollution.

Description

(1) Technical field [0001] The invention relates to a method for preparing tert-butyl carbazate, in particular to a method for preparing tert-butyl carbazate in an ionic liquid under the catalysis of a solid base in one pot. (2) Background technology [0002] Tert-butyl carbazate is also known as tert-butylcarbazole, or tert-butylcarbamate, etc. It is an amino-protecting agent and an intermediate of important medicines. The 9-peptide synthetic analog used to synthesize gonadotropin (GnRH), can promote the release of luteinizing hormone and follicle hormone from the anterior pituitary gland, regulate the secretion of gonadal hormone, and can treat reproductive system diseases, prostate cancer and children's idiopathic true precocious puberty etc., can also synthesize leucine enkephalin hydrazine hydrazide analogs and anticancer drugs, and it has also been reported to be used in the synthesis of anti-AIDS drugs in recent years. At present, there are few domestic manufacturer...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C281/02
Inventor 裴文孙莉汪祝胜潘镇浩全嘉铭陶荣哨
Owner 苏州卫优知识产权运营有限公司
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