196597-78-1Relevant articles and documents
Preparation method 1, 2, 6, 7 - tetrahydro - 8H - indeno [5, 4 - b] furan -8 - ketone
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, (2021/09/21)
The invention provides a preparation method of 1, 2, 6, 7 - tetrahydro - 8H - indeno [5, 4 - b] furan -8 - ketone, which comprises the following steps of (1) taking compound II as a raw material, adding a halogenating agent and hydrogen peroxide to halogenate to obtain compound III: 3 - X - 4 - hydroxybenzoic acid. (2) The compound III was mixed with 1 - bromo -2 - chloroethane and an alkali metal hydroxide to give compound IV: 3 - X - 4 - (2 - chloroethoxy) phenylpropionic acid. (3) Compound IV was added to nitrobenzene, and an acylation reagent was added to react to give compound V: 3 - X - 4 - (2 - chloroethoxy) phenylpropionyl chloride. (4) To the reaction system, aluminum trichloride was added to react to give compound VI: 4 - X - 1, 2, 6, 7 - tetrahydro - 8H - indeno [5, 4 - b] furan -8 - ketone. (5) Compound VI was added to toluene, and a palladium carbon and sodium acetate aqueous solution were added to catalyze hydrogenation to give compound I: 1, 2, 6, 7 - tetrahydro - 8H - indeno [5, 4 - b] furan -8 - ketone.
A thunder-US for amine preparation method for the synthesis of the key intermediate
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, (2019/10/02)
The invention discloses a synthetic preparation method for a key intermediate of ramelteon 1,2,6,7-tretrahydro-8H-indeno[5,4-b]furan-8-one. According to the preparation method, by taking 2,3-dihydrobenzofuran-4-formaldehyde as an initial raw material, the key intermediate of ramelteon 1,2,6,7-tretrahydro-8H-indeno[5,4-b]furan-8-one is synthesized through Grignard reaction, oxidizing reaction and Nazarov cyclization reaction. The preparation method has the advantages of being high in reaction selectivity, few in side effects, high in total yield and quality, environmental-friendly, simple and convenient in process operation, high in stability and controllability and the like, and is suitable for industrial large-scaled production.
A method of preparing intermediates lei Meiti amine
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Paragraph 0063; 0064, (2017/02/24)
The invention relates to a preparation method of a Ramelteon intermediate. The Ramelteon intermediate is prepared by taking 4,5-dibromo-1,2,6,7-tetrahydro-8H-indeno[5,4-b]furan-8-one as a raw material, and then subjecting the raw material to a series of simple reactions so as to obtain the Ramelteon intermediate. The preparation method of the Ramelteon intermediate has the advantages of high yield, high product purity, simple operation, low cost, and suitability for mass production.