- 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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- Pharmaceutical compositions containing isoquinoline derivatives
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Pharmaceutical compositions containing an isoquinoline derivative exhibit an excellent inhibitory action to an isozyme of phosphodiesterase of the type IV (PDEIV). The active component of the pharmaceutical composition is an isoquinoline derivative which is represented by the general formula: STR1 wherein R is an ethoxy group, or which is a pharmaceutically-acceptable salt of a compound represented by said formula. The isoquinoline derivatives have an excellent inhibitory action which is highly specific to PDEIV. They are highly useful as pharmaceuticals such as antidepressive agents, tranquilizers, antidemential agents, antiinflammatory agents, antiallergic agents, antiasthmatic agents, liver-protecting agents, and diuretic agents.
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