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Method for preparing polysubstituted 3,4-dihydro-3-methyl-2H-1,4-benzoxazine-2-one

A multi-substituted, benzoxazine technology, applied in the field of preparing multi-substituted 3,4-dihydro-3-methyl-2H-1,4-benzoxazin-2-one, can solve the harsh reaction conditions , high cost of raw materials, cumbersome operation steps, etc., to achieve the effect of easy processing and reduced environmental protection costs

Inactive Publication Date: 2009-06-10
EAST CHINA UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved in the present invention is to disclose a new preparation method of 3,4-dihydro-3-methyl-2H-1,4-benzoxazin-2-one to overcome the existing problems of the prior art The disadvantages of expensive raw materials, cumbersome operation steps and harsh reaction conditions

Method used

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  • Method for preparing polysubstituted 3,4-dihydro-3-methyl-2H-1,4-benzoxazine-2-one

Examples

Experimental program
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Effect test

Embodiment 1

[0020] Grind coconut shell activated carbon and sieve to obtain activated carbon powder of 300-400 mesh. Add a certain amount of activated carbon to 10wt.% nitric acid, stir in 80°C water bath for 2 hours, then filter and wash with distilled water until neutral. Water vapor is then processed, dried, and set aside. Dissolve chloroplatinic acid in deionized water to make 1.7×10 -2 mol / L chloroplatinic acid solution. Add 10g of activated carbon treated with amine acid into 165mL of chloroplatinic acid aqueous solution, soak for 2 hours, then add 8mL of formaldehyde for reduction, and at the same time add saturated sodium bicarbonate solution dropwise, control the pH value to about 9, and react until the pH value remains unchanged. Filter and dry to obtain a Pt / C catalyst with a Pt content of 5 wt.%.

[0021] The reaction process is that 0.10mol o-nitrophenol, 0.12moL pyruvic acid, 2g 5wt.% Pt / C catalyst, 240mL 80v / v% isopropanol aqueous solution are added in a 0.5L autoclave wi...

Embodiment 2

[0023] Dissolve palladium chloride in deionized water to make a 1.7×10 -2 mol / L palladium chloride solution, get 278mL, add 10g coconut shell activated carbon (300 mesh) processed by the method of Example 1 and soak for 2h, then add 8ml formaldehyde for reduction, drop saturated sodium bicarbonate solution simultaneously, control the pH value is about 9, react until the pH value remains unchanged, filter and dry to obtain a Pd / C catalyst with a Pd content of 5wt.%.

[0024] Add 0.10mol of o-nitrophenol, 0.20mol of pyruvic acid, 2g of 5wt.% Pd / C catalyst, and 240mL of 80v / v% methanol aqueous solution into a 0.5L autoclave with a mechanical stirring device, and completely fill the air in the autoclave with hydrogen After the replacement, under the conditions of 2.0 MPa hydrogen pressure and 20° C., turn on the mechanical stirring at a speed of 1000 rpm, and react for 10 h. After the reaction was completed, the catalyst was directly filtered, 10 mL of concentrated hydrochloric a...

Embodiment 3

[0026] In the same manner as in Example 2, using the 5wt.% Pd / C catalyst that has been used 20 times, add 0.10mol o-nitrophenol, 0.20mol pyruvic acid, 240mL 80v / v% isopropyl Add the alcohol aqueous solution into a 0.5L autoclave with a mechanical stirring device, completely replace the air in the autoclave with hydrogen, and then turn on the mechanical stirring at a hydrogen pressure of 2.0MPa and 20°C at a speed of 1000rpm, and react for 10h . After the reaction was completed, the catalyst was directly filtered, 10 mL of concentrated hydrochloric acid was added to the filtrate, and the solvent was removed by distillation under reduced pressure using a rotary evaporator. 100 mL of dichloromethane and 300 mL of saturated aqueous sodium bicarbonate were added, and the solution was separated to obtain an oil phase and an aqueous phase. Separate the oil phase, add anhydrous magnesium sulfate to the oil phase to remove water, filter to obtain an anhydrous oil phase, and then conce...

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Abstract

The invention discloses a method for producing multi-substituted 3,4-bihydrogen-3-methyl-2H-1,4- benzothiazine-2-ketones. The method comprises the following steps: all kinds of multi-substituted 3,4-bihydrogen-3-methyl-2H-1,4- benzothiazine-2-ketone are produced from multiple substituted o-nitryl phenol through one-pot synthesis of catalytic hydrogenation / reduction ammoniation / esterification with rare metals are used as the catalysts in a mixed solution of an alcohol and water. The method provided by the invention uses o-nitryl phenol as the norm to achieve a mole yield more than 25 percent of multi-substituted 3,4-bihydrogen-3-methyl-2H-1,4- benzothiazine-2-ketones. The cheap raw material for the reaction is cheap and the one-pot synthesis is used, so that the technology provided by the invention for producing multi-substituted 3,4-bihydrogen-3-methyl-2H-1,4- benzothiazine-2-ketones is an effective method and has a great prospect in the industrialized production.

Description

technical field [0001] The present invention relates to a preparation method of multi-substituted 3,4-dihydro-3-methyl-2H-1,4-benzoxazin-2-one, which comprises multi-substituted o-nitrophenol and pyruvic acid Various polysubstituted 3,4-dihydro-3-methyl-2H-1,4-benzoxazin-2-ones were prepared by catalytic hydrogenation / reductive amination / esterification in one pot. Background technique [0002] Substituted 3,4-dihydro-3-methyl-2H-1,4-benzoxazin-2-one is a class of compounds with good biological activity. In view of this, many synthetic methods and preparation processes have come out one after another . [0003] Early 3,4-dihydro-3-methyl-2H-1,4-benzoxazin-2-one was catalyzed by 3-methyl-2H-1,4-benzoxazin-2-one Hydrogen is obtained (GB815279, 1959). The patent applied by Farbenfabriken Bayer Aktiengesellschaft company describes the condensation reaction of pyruvate and o-aminophenol to prepare 3-methyl-2H-1,4-benzoxazin-2-one, which is then added under the catalysis of Pd / C...

Claims

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Application Information

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IPC IPC(8): C07D265/36
Inventor 王幸宜童晓峰金中豪李到
Owner EAST CHINA UNIV OF SCI & TECH
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