- Novel method for preparing drotaverine hydrochloride intermediate
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The invention discloses a novel method for preparing a drotaverine hydrochloride intermediate, belonging to the technical field of medicine synthesis. The preparation method comprises the following steps: preparing an intermediate 3,4-diethoxyphenylacetic acid with 1,2-diethoxybenzene as a raw material, and preparing the intermediate 3,4-diethoxyphenylacetamide with 3,4-diethoxyphenylacetic acid as a raw material. According to the novel process for preparing the drotaverine hydrochloride intermediate, a method for directly preparing 3,4-diethoxyphenylacetic acid and 3,4-diethoxyphenylethylamine is adopted, and a process for preparing 3,4-diethoxyphenylacetonitrile is avoided, so a reaction step of using sodium cyanide is avoided.
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- Novel preparation method of drotaverine hydrochloride intermediate
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The invention discloses a novel preparation method of a drotaverine hydrochloride intermediate. The preparation method comprises the steps that 1, 4-bromopyrocatechol serves as the raw material and issubjected to an ethylation reaction under the action of iodoethane or diethyl sulfate, and 1,2-diethoxy-4-bromobenzene is prepared; 2, 1,2-diethoxy-4-bromobenzene is subjected to a Suzuki-Miyaura coupling reaction and reacts with ethyl bromoacetate or methyl bromoacetate to prepare 3,4-diethoxyphenylaceticacid ester; 3, 3,4-diethoxyphenylaceticacid is hydrolyzed to prepare 3,4-diethoxyphenylaceticacid; 4, 3,4-diethoxyphenylaceticacid ester and ammonia are prepared into 3,4-diethoxyphenylacetamide; 5, 3,4-diethoxyphenylacetamide is reduced to prepare 3,4-diethoxyphenethylamine. The direct preparation method is used; in the process of preparing 3,4-diethoxyphenyl acetonitrile, application of sodium cyanide is avoided; when 3,4-diethoxyphenethylamine is prepared, lithium aluminium hydride isused for reduction, and a pressurized hydrogenation method is prevented from being used, so that the problems about safety and environment pollution are effectively solved, the process is simple andeasy to implement, and the practicality is high.
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