- Method for preparing carvedilol intermediate N-benzyl carvedilol
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The invention relates to a method for preparing a carvedilol intermediate N-benzyl carvedilol, wherein the method comprises the following steps: (1) firstly, loading a compound II, a compound III, sodium hydroxide and a solvent into a reaction kettle, heating up to a reaction temperature, and carrying out a vigorous stirring reaction, to obtain a reaction material liquid; (2) in the reaction process, pumping the reaction material liquid into an external circulation water removal system filled with a water removal agent at a certain flow velocity, and carrying out circulation water removal; and (3) after the reaction is finished, discharging a product I from the bottom of the reaction kettle, and recrystallizing to obtain a compound I. Compared with the prior art, water generated in the nucleophilic substitution reaction of the compound II and the compound III is removed timely by the external circulation water removal system, the conversion rate of the reaction raw materials of the compound II and the compound III is greatly increased, low-energy-consumption, simple and quick continuous production is achieved, the yield of the obtained reaction product I is more than 90%, and the chemical purity is more than 97%.
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Paragraph 0012; 0022; 0023; 0024; 0025; 0026; 0027-0035
(2017/05/23)
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- Synthesis and characterization of potential impurities of carvedilol, an antihypertensive drug
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Carvedilol (Coreg) is a nonselective -adrenergic blocking agent with vasodilating activity. It is used for the treatment of congestive heart failure and hypertension. During the bulk synthesis of carvedilol, we have observed six impurities: Imp-I, Imp-II, Imp-III, Imp-IV, Imp-V, and Imp-VI. The present work describes the synthesis and characterization of these impurities. Copyright
- Rao, Somisetti Narender,Sitaramaiah, Devarasetty,Srimannarayana, Kema,Rao, Challa Nageswar,Rao, Peddi Srinivasa,Babu, K. Sudhakar
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- PROCESS FOR PREPARATION OF 1-(9H-CARBAZOL-4-YLOXY)-3-[[2-(2- METHOXYPHENOXY) ETHYL] AMINO]-2-PROPANOL
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The present invention relates to a process for preparation of l-(9H-carbazol-4-yloxy)-3- [[2-(2-methoxyphenoxy) ethyl] amino]-2-propanol and its salts comprising; a)reacting 1- (9H-carbazol-4-yloxy)-3-arylmethylamino-2-propanol or its 9-substituted derivatives with 2-(2-methoxyphenoxy)-haloethane; and b) deprotecting the resulting intermediate to obtain l-(9H-carbazol— 4— yloxy)-3-[[2-(2-methoxyphenoxy)ethyl] amino]-2-propanol in free form or its acid addition salt, which are pharmaceutically valuable compounds.
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Page/Page column 11-12
(2009/10/22)
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- PROCESS FOR THE PREPARATION OF CARVEDILOL
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A process for the preparation of carvedilol of formula (I) (I) either in enantiomeric substantially pure form, or as an enantiomeric mixture, optionally as a pharmaceutically acceptable salt thereof, which process comprises reacting 2,3-eopxypropoxy carbazole of formula (II) (II) or the R or S enantiomer thereof, with N-[2-(2-methoxy-phenoxy)ethyl]-benzylamine of formula (V) (V) to yield benzyl carvedilol of formula (VI) (VI) which is debenzylated by catalytic hydrogenation to yield carvedilol of formula (I), either in enantiomeric substantially pure form, or as an enantiomeric mixture, and if desired reacting the thus formed carvedilol of formula (I) with an inorganic or organic acid to yield a pharmaceutically acceptable salt thereof, and/or, if desired, separating the enantiomers. The above process is characterised in that reaction of said 2,3-epoxypropoxy carbazole of formula (II) with said N-[2-(2-methoxy-phenoxy)ethyl]-benzylamine of formula (V) is carried out in water as the reaction medium. The present invention further provides carvedilol of formula (I) prepared by a process as described above, and pharmaceutical compositions containing the same and therapeutic uses thereof.
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Page/Page column 15
(2008/06/13)
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- A PROCESS FOR PREPARATION OF 1-[9H-CARBAZOL-4-YLOXY]- 3-[{2-(2-(-(METHOXY)PHENOXY)-ETHYL}-AMINO]-PROPAN-2-OL
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The present invention provides a process for preparation of 1-[9H-carbazol-4-yloxy]-3-[{2-(2-(methoxy)phenoxy)-ethyl}-amino]-propan-2-ol, a compound of formula 1 in racemic form or in the form of optically active R or S enantiomer or its pharmaceutically acceptable salt, comprising, reacting 4-(oxiranylmethoxy)-9H-carbazole, a compound of formula (2) or the R or S enantiomer thereof with a compound of formula (5), wherein R1 is benzyl or substituted benzyl group, in an aprotic organic solvent in presence of a catalyst to obtain a compound of formula (6), or the R or S enantiomer thereof, wherein R1 is as defined above. The resultant compound of formula (6) is subjected to debenzylation reaction by catalytic hydrogenation to obtain the compound of formula (1), if desired converting the resultant compound of formula (1) to a pharmaceutically acceptable salt thereof.
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Page 13; 17-18
(2008/06/13)
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- Process for preparing heterocyclic indene analogs
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A process for the preparation heterocyclic indene analogs, especially with the preparation of 4-hydroxycarbazole or N-protected 4-hydroxycarbazole, involves cyclocarbonylation followed by saponification. This process avoids high temperatures and high catalyst loadings.
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