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Selective alkylation reaction of acid anhydride or ester

An alkylation reaction and selectivity technology, which is applied in the field of acid anhydride or ester selective alkylation reaction, can solve the problems of low yield of monoalkylation, difficult product separation and high synthesis cost, and achieves easy control of the reaction and reduced The effect of low cost and synthesis cost

Inactive Publication Date: 2008-11-05
LANZHOU UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The inventor had achieved success many years ago with a stronger electrophile - alkyllithium and phthalic anhydride at a higher temperature, but in this reaction the desired monoalkylated product was obtained In addition, a part of double-alkylated products were obtained, which brought certain difficulties to the separation of products, and the synthesis cost was relatively high.
[0005] Similarly, the addition reaction of esters and Grignard reagents generally produces tertiary alcohols. Although the intermediate product of this reaction is a ketone, the reaction cannot be controlled to the ketone stage, because the ketone carbonyl in the molecule is more active than the ester carbonyl in the molecule. The activity is higher, and the reaction is difficult to stop at the step of generating ketones, and the final product is mostly a mixture of ketones and alcohols; that is, a mixture of mono-alkylated products of esters and di-alkylated products of esters, and there are also products Problems with low yields of separation and monoalkylation

Method used

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Examples

Experimental program
Comparison scheme
Effect test

example 1

[0022] 0.05 moles, that is, 7.4 grams of phthalic anhydride and 0.1 grams (less than 2%) CuI of a catalytic amount are dissolved in 50 ml of anhydrous tetrahydrofuran, under argon protection, 0.1 moles are added dropwise under stirring at room temperature (with 2.4 grams of metal magnesium and 13.7g of n-bromobutane in 50ml of anhydrous ether) alkyl Grignard reagent, add Grignard reagent dropwise for about half an hour, react for 12-15 hours, add 50ml of dilute hydrochloric acid 2mol solution to stop the reaction , 25ml×3 ether extraction, 25ml of saturated sodium bicarbonate aqueous solution washed ether extract 3-5 times, saturated saline solution washed 1-2 times, dried over anhydrous magnesium sulfate, distilled off the solvent to obtain the crude product 3-butene isobenzene Furan-1-3(hydrogen)-one 8.93 g, yield 95%. The pure product separated by column chromatography conforms to the predetermined structure by TCL and spectral analysis. The color change in the reaction pr...

example 2

[0024] Using 7 grams of 4-cyclohexene-1,2-dianhydride as a raw material, the amount of Grignard reagent is 0.075 moles (diethyl ether solution prepared with 1.8 grams of magnesium metal and a corresponding amount of n-bromobutane) alkyl Grignard reagent. The raw materials and 0.1 g of cuprous iodide were dissolved in anhydrous tetrahydrofuran, and the Grignard reagent was added dropwise. Finally, 8.5 g of the target product (3Z)-3-butene-3a,4,7,7a-tetrahydroisobenzofuran-1-3(hydrogen)-one was obtained with a yield of 96%. The reaction operation and aftertreatment are the same as Example 1, the color change in the reaction process is light yellow→brown→transparent yellow, and the reaction time is 9-11 hours.

example 3

[0026] 7.51 grams of 1-cyclohexene-1,2-dioic anhydride and 0.1 gram of cuprous iodide were dissolved in anhydrous tetrahydrofuran, and 0.1 mole (made with 2.4 grams of metal magnesium and a corresponding amount of brominated n-butane) was added dropwise. 8.9 grams of target product (3Z)-3-butene-4,5,6,7-tetrahydroisobenzofuran-1-3 (hydrogen)-ketone at last , yield 93%. During the reaction process, the color changes from gray to brown to yellow. Operation is the same as Example 1, but the reaction time is 5-6 hours.

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PUM

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Abstract

The invention discloses a method of organic synthesis, exactly said is selective alkanisation reaction of acid anhydride or ester. The acid anhydride or ester selective alkanisation reaction of this invention is using acid anhydride or ester as substrate, reacting with Grignard reagent in catalysis of halogenating cuprous. The method of this invention is suit to industral magnification, furthermore, the raw material is easy to get, the sythesis cost is low, the cost of this invention os lower than the technique in existence, the productivity is higher than the technique in existence. This invention provides new sythesis method for product that is hard to get by common method.

Description

technical field [0001] The present invention relates to a kind of method of organic synthesis, specifically relate to acid anhydride or ester selective alkylation reaction. Background technique [0002] The products obtained from the selective alkylation of acid anhydrides or esters have attracted much attention in the industry because of their various activities. Such as: some 3-hydrocarbyl phthalides, such as (3Z)-3-buteneisobenzofuran-1-3(hydrogen)-one, 3-n-butylisobenzofuran-1-3(hydrogen)-one , 3-n-propylisobenzofuran-1-3(hydrogen)-one, has been registered as a fragrance by the US Food and Drug Administration. Another example is (3Z)-3-butene-4,5,6,7-tetrahydroisobenzofuran-1-3(hydrogen)-one (6,7-dihydroligustilide), etc. have good Adding an appropriate amount of phthalides to soaps and fruit juices will produce a pleasant fragrance and become a commonly used spice. In addition, some compounds in this class also have good pharmacological activity, such as: 3-alkylphth...

Claims

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Application Information

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IPC IPC(8): C07B49/00B01J27/122
Inventor 李绍白吴莉叶谦
Owner LANZHOU UNIVERSITY