METHOD FOR PREPARING PREGABALIN INTERMEDIATE 3-ISOBUTYLGLUTARIC ACID MONOAMIDE
Provided is a method for preparing a pregabalin intermediate 3-isobutylglutaric acid monoamide. The method comprises: 1) adding 3-isobutylglutaric acid and urea into a first organic solvent; 2) keeping warm and refluxing when heated to 100-140° C.; 3) adding water when cooled to 70-90° C.; 4) adding...
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Main Authors | , , , , |
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Format | Patent |
Language | English |
Published |
23.05.2019
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Subjects | |
Online Access | Get full text |
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Summary: | Provided is a method for preparing a pregabalin intermediate 3-isobutylglutaric acid monoamide. The method comprises: 1) adding 3-isobutylglutaric acid and urea into a first organic solvent; 2) keeping warm and refluxing when heated to 100-140° C.; 3) adding water when cooled to 70-90° C.; 4) adding an ion membrane alkaline when cooled to 40-60° C., adjusting the pH to 11.0-14.0, then keeping warm at 40-60° C.; 5) when finished keeping warm, removing an organic layer; 6) adding an acid into the water layer to adjust the pH to 1.0-3.0; 7) extracting the solution acquired in step 6) by using a second organic solvent of a total volume of V, vacuum distilling 0.5-0.6 V of the organic solvent from an organic layer acquired by extraction; and 8) cooling to 0-15° C. and crystallizing to acquire 3-isobutylglutaric acid monoamide. |
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Bibliography: | Application Number: US201716313262 |