Efficient process for production of carvedilol phosphate
First Claim
1. An efficient process for preparation of carvedilol dihydrogen phosphate hemihydrate salt in high yield comprising the steps of:
- a) dissolving carvedilol free base in a suitable solvent and water mixture;
b) generating a phosphate salt of the carvedilol using a suitable phosphate forming agent selected from the group consisting of phosphorous pentoxide (phosphorus pentoxide), polyphosphoric acid, dipotassium hydrogen phosphate, ammonium dihydrogen ortho phosphate and sodium dihydrogen ortho phosphate to obtain carvedilol dihydrogen phosphate salt; and
c) isolating the carvedilol dihydrogen phosphate hemihydrate salt from the reaction mass.
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Abstract
A novel cost effective process for the synthesis of phosphate salts of 1-(9H-carbazol-4yloxy)-3-[[2-(2-methoxyphenoxy)ethyl]amino]-propan-2-ol, (carvedilol phosphate) of formula (II) with high yields and purity is disclosed. More particularly, the invention discloses a process for preparation of crystalline phosphate salts of carvedilol using various phosphate forming reagents such as phosphorous pentoxide, polyphosphoric acid, dipotassium hydrogen phosphate, ammonium dihydrogen ortho phosphate, and sodium dihydrogen ortho phosphate in solvents selected from Acetonitrile, acetone and tetrahydrofuran. The solvents used to prepare solvates of carvedilol dihydrogen phosphate are methanol, ethanol and isopropyl alcohol.
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11 Claims
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1. An efficient process for preparation of carvedilol dihydrogen phosphate hemihydrate salt in high yield comprising the steps of:
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a) dissolving carvedilol free base in a suitable solvent and water mixture; b) generating a phosphate salt of the carvedilol using a suitable phosphate forming agent selected from the group consisting of phosphorous pentoxide (phosphorus pentoxide), polyphosphoric acid, dipotassium hydrogen phosphate, ammonium dihydrogen ortho phosphate and sodium dihydrogen ortho phosphate to obtain carvedilol dihydrogen phosphate salt; and c) isolating the carvedilol dihydrogen phosphate hemihydrate salt from the reaction mass. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification