Preparation method of 5, 6-methylenedioxy indole

A technology of methylenedioxyindole and dimethoxy, which is applied in the field of preparation of 5,6-methylenedioxyindole, can solve problems such as unsuitability for large-scale production and complicated operation, and achieve High productivity, simple operation, and cost reduction effects

CN112574226AInactive Publication Date: 2021-03-30BTC PHARMA TECH CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2021-03-30
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention provides a preparation method of 5, 6-methylenedioxy indole. The preparation method comprises the following steps: reacting 3, 4-methylenedioxy aniline serving as a raw material with benzene sulfonyl chloride to obtain A2, reacting A2 with 2, 2-dimethoxy-1-bromoethane to obtain a precursor A3 of a ring closing reaction, performing ring closing on A3 under the action of Lewis acid toobtain A4, and removing a protecting group of amino by using alkali to obtain the final 5, 6-methylenedioxy indole. according to the invention, 3, 4-methylenedioxy aniline is used as a raw material, nitro is prevented from being reduced into amino, the price of the compound is low, the cyclization reaction can be completed at normal temperature under the action of Lewis acid, and extreme conditions of high temperature or a strong reducing agent are avoided. The whole synthesis operation is simple, the post-treatment is easy, and the generated three wastes are few. The solvent in the reaction process can be reused, so that the cost is reduced, the operation is simple, the yield is higher, and the product with the purity of more than 98% can be obtained. The method is suitable for mass production and has obvious economic benefits.
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Description

technical field

[0001] The invention belongs to the technical field of chemical synthesis, and in particular relates to a preparation method of 5,6-methylenedioxyindole. Background technique

[0002] 5,6-methylenedioxyindole belongs to indole compounds, and its structural formula is as follows:

[0003]

[0004] Indole compounds are widely used in the fields of medicine and pesticides. The traditional synthetic method is to use nitrostyrene compounds as raw materials and obtain products through reductive cyclization. The reductive amination reaction needs to be done under high temperature and high pressure, the operation is complicated, has certain risks, and is not suitable for large-scale production. Contents of the invention

[0005] In order to solve the deficiencies of the prior art, the invention provides a preparation method of 5,6-methylenedioxyindole.

[0006] The purpose of the present invention is achieved through the following technical solutions: [000...

Examples

Embodiment Construction

[0026] The technical scheme of the present invention is specifically described below in conjunction with the examples, and the present invention discloses a preparation method of 5,6-methylenedioxyindole

[0027] first step reaction

[0028]

[0029] Add 48Kg DMF, 3.6kg A1 and 3.1kg pyridine to the 100L kettle in sequence, and add 6.55kg benzenesulfonyl chloride dropwise at a temperature of 80-100°C. Insulate at 80°C for 24h. HPLC detects that A1 disappears, washed with 30kg of water, 24kg of 2N hydrochloric acid, and 10kg of water. Spin dry, beat with 8 kg of ether, filter, spin dry the filtrate and beat with 1 kg of petroleum ether, combine the filter cakes twice, and dry to obtain 7.2 kg of rose-red solid. The yield was 95%, and the HPLC purity was 99%.

[0030] second step reaction

[0031]

[0032] Add 13kg THF to the kettle, and slowly add 4.25kg sodium hydrogen. Dissolve 7.2kg of A2 in 20kg of THF and add it dropwise into the kettle, keeping the temperature b...