- Synthetic method of 1,4,6,7-tetrahydropyran[4,3-C]pyrazole-3-carboxylic acid
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The invention discloses a synthetic method of 1,4,6,7-tetrahydropyran[4,3-C]pyrazole-3-carboxylic acid. The synthetic method comprises the following steps: preparing 2-oxo-2-(4.oxotetrahydro-2H-pyran-3-yl)acetate (2) from diethyl oxalate and tetrahydropyranone; carrying out ring closure on 2-oxo-2-(4.oxotetrahydro-2H-pyran-3-yl)acetate (2) and hydrazine hydrate so as to generate 1,4,6,7-tetrahydropyran[4,3-c]pyrazole-3-carboxylic acid ethyl ester (3); and finally, carrying out hydrolysis reaction, so as to obtain a target product, namely 1,4,6,7-tetrahydropyran[4,3-C]pyrazole-3-carboxylic acid. The synthetic method solves the problems of expensive raw materials and low yield in the prior art. The route is mild in conditions and easy for purification, the final product with relatively highyield and high purity is prepared, and the route is suitable for process amplification.
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- Tricyclic azole derivatives
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The present invention relates to the compounds of formula I: their pharmaceutically acceptable salts or esters, enantiomeric forms, diastereoisomers and racemates, the preparation of the above-mentioned compounds, pharmaceutical compositions containing th
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(2010/11/24)
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