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Preparation method of 5-halogenated pentanoate

A technology of halogenated valerate and halogenated valeronitrile, which is applied in the field of preparation of 5-halogenated valerate, can solve the problems of expensive chemical reagents and low purity, and achieve the effect of simple reaction and easy operation

Inactive Publication Date: 2011-05-25
ZHEJIANG MEDICINE CO LTD XINCHANG PHAMACEUTICAL FACTORY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The preparation of δ-cyclopentarolactone will use flammable and explosive hydrogen peroxide and catalyst iodine or noble metal complexes, and it will be prepared by Baeyer-Villiger oxidation reaction (Synthetic Communications, 37(23), 4093-4097; 2007) , and δ-cyclopentarolactone will undergo self-polymerization, which is an expensive chemical reagent and has not been domestically produced so far
[0004] Wherein, 5-iodovaleric acid ester often adopts the preparation method (Journal of Organic Chemistry, 48 (25), 4976-86; 1983) of conventional sodium iodide iodo 5-chlorovaleric acid ester, and the yield only reaches 80% , and the yield of the preparation method of iodo 5-bromovalerate can reach 96% (Journal of the American Chemical Society, 127 (11), 3678-3679; 2005), but the purity is not high

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] In a 500mL four-necked flask, put 117.6g (1.0mol) of 5-chlorovaleronitrile, 35g (1.1mol) of methanol, and 200mL of n-hexane to stir, control the temperature at -10~-5°C, and slowly introduce anhydrous hydrogen chloride gas, When the weight of the system is about 40g, remove the freezer, raise the temperature naturally to 25-30°C, stir and react for 2h, add 100mL of water, separate the layers, wash the oil layer with water to become weakly acidic, and concentrate to obtain 143g of methyl 5-chlorovaleric acid. 95%, GC analysis content 97.5%.

[0026] ESI-MS: 151(M+1). 1 H NMR (CDCl 3 , 200MHz) δ: 3.67(3H, s), 3.38(2H, m), 2.25(1H, m), 1.68(2H, m), 1.57(2H, m).

Embodiment 2

[0028] In a 500mL four-necked flask, put 117.6g (1.0mol) of 5-chlorovaleronitrile, 70g (1.5mol) of ethanol, and 100mL of petroleum ether and stir, control the temperature at -5~0°C, and slowly introduce anhydrous hydrogen chloride gas until The weight of the system increased by about 50g, removed the freezer, raised the temperature to 30-35°C, stirred and reacted for 12h, added 100mL of water, separated into layers, washed the oil layer with water to become weakly acidic, and concentrated to obtain 150g of ethyl 5-chlorovalerate, with a yield of 91.2% , GC analysis content 98%.

[0029] ESI-MS: 165(M+1). 1 H NMR (CDCl 3 , 200MHz) δ: 4.12(2H, m), 3.38(2H, m), 2.25(1H, m), 1.68(2H, m), 1.57(2H, m), 1.30(3H, m).

Embodiment 3

[0031] In a 500mL four-neck flask, put 162g (1.0mol) of 5-bromovaleronitrile, 42g (1.3mol) of methanol, and 100mL of dichloromethane and stir, control the temperature at -10~0°C, and slowly introduce anhydrous hydrogen chloride gas until The weight of the system is about 45g, remove the freezer, heat up to 20-30°C, stir for 6 hours, add 100mL of water, separate layers, wash the oil layer with water to become weakly acidic, and concentrate to obtain 180g of methyl 5-bromovalerate, yield 92.3% , GC analysis content 98.1%.

[0032] ESI-MS: 195, 197 (M+1). 1 H NMR (CDCl 3 , 200MHz) δ: 3.67(3H, s), 3.30(2H, m), 2.25(1H, m), 1.79(2H, m), 1.68(2H, m).

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PUM

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Abstract

The invention provides a preparation method of 5-halogenated pentanoate, which comprises the following steps of: (1) mixing and stirring 5-halogenated valeronitrile, low-grade saturated monobasic alcohol and a non-polar solvent, and controlling the reaction temperature to be between -10 and -5 DEG C; (2) introducing anhydrous hydrogen chloride into the mixture obtained in the step (1), cooling the mixture when the weight of the system is increased by 40 to 60 grams, naturally raising the temperature to be between 20 and 35 DEG C, and stirring the mixture; and (3) adding water into the mixture obtained in the step (2), washing an oil layer by using water after demixing until the mixture is weakly acidic, and concentrating the mixture to obtain the 5-halogenated pentanoate. Compared with the prior art, the preparation method has the advantages that: raw materials are low in cost and readily available, the method is simple in reaction, and convenient for operation; besides, the yield is over 91 percent, and the purity of the product is over 96 weight percent.

Description

technical field [0001] The invention relates to the field of organic chemistry, in particular to a preparation method of 5-halogenated valerate. Background technique [0002] Biotin, also known as vitamin H or vitamin B7, is necessary for the entire biological world as an auxin. Since biotin was isolated from bovine liver in 1941, as an important vitamin, it has been the object of synthesis by scientists from all over the world. However, the problems of many reaction steps, expensive reagents and harsh reaction conditions are difficult to solve. Among them, 5-halogenated valerate is a very important pharmaceutical and chemical intermediate, which best meets the structural requirements of the key side chain of biotin, and has now become an important substance for the synthesis of the key side chain of biotin. Therefore, 5 The research on the synthesis of -halogenated valeric acid ester as the starting material of biotin side chain has attracted much attention (Chen Fen'er C...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C69/63C07C67/22
Inventor 陈建辉皮士卿
Owner ZHEJIANG MEDICINE CO LTD XINCHANG PHAMACEUTICAL FACTORY