- Resolution method of clemastine fumarate intermediate
-
The invention relates to the technical field of raw material medicine synthesis, and discloses a resolution method of a clemastine fumarate intermediate. The invention discloses a resolution method ofa clemastine fumarate intermediate. The used resolving agent is malic acid and bis(p-methylbenzoyl) tartaric acid, and the two resolving agents are D-type or L-type or one of D and L racemates, wherein the molar ratio of the using amount of the resolving agents to N-methyl-2 drops (2-hydroxyethyl) pyrrolidine is 1.0-2.0, and preferably, the molar multiple of the resolving agents is 1.0-1.3. The invention discloses a resolution method of a clemastine fumarate intermediate. After the N-methyl-2 (2-ethoxyl) pyrrolidine is resoluted, the yield can be stabilized above 48%. The method has the advantages of simple operation, good chiral purity, strong operationality, easy industrialization, solving of the problems of high production cost and large resolution technology difficulty of the synthesis method reported in literature, solving of the problems of increase of the production cost and the resolution technology difficulty caused by the first synthesis and the second chiral resolution, wide development space, and high promotion value.
- -
-
Paragraph 0021; 0024-0025
(2020/05/11)
-
- Preparation method of clomastine fumarate with high chiral purity
-
The invention discloses a preparation method of chlormastine fumarate with high chiral purity. The preparation method comprises the following five steps: step 1, taking D-arginine as a resolving agentto resolve a compound N-methyl-2-(2-hydroxyethyl) pyrrolidine shown in a formula 2 to obtain a compound shown in a formula 3; step 2, reacting the compound shown in the formula 3 with thionyl chloride for chlorination to obtain a compound shown in a formula 4; step 3, reacting the compound shown in the formula 4 with a compound 1-((4-chlorphenyl)-1-phenyl) ethanol shown in a formula 5 under the condition that sodium amide is strong base to obtain a compound shown in a formula 6; step 4, resolving the compound shown in the formula 6 by adopting tartaric acid to remove chiral isomer impurities,and obtaining a compound shown in a formula 7 at the same time; and step 5, salifying the compound shown in the formula 7 and fumaric acid to obtain a compound chlormastine fumarate shown in a formula 1. The prepared clomastine fumarate bulk drug has high chiral purity, the product quality meets the injection drug requirements specified in pharmacopeia, the technological process is simple and easy to control, the operability is high, and industrial production can be achieved.
- -
-
Paragraph 0016; 0020
(2020/07/15)
-
- Asymmetric synthesis of H1 receptor antagonist (R,R)-clemastine
-
The first asymmetric synthesis of (R,R)-clemastine (1) has been accomplished by the coupling of (R)-tertiary alcohol 2 and (R)-chloroethylpyrrolidine 3 via O-alkylation. (R)-Tertiary alcohol 2 was synthesized by stereoselective alkylation of chiral α-benz
- Lee, Sun Young,Jung, Jung Wha,Kim, Tae-Hyun,Kim, Hee-Doo
-
p. 2131 - 2136
(2015/12/08)
-
- Synthesis of (-)-(S, S)-clemastine by invertive N → C aryl migration in a lithiated carbamate
-
The first enantioselective synthesis of the antihistamine agent clemastine, as its (S,S)-stereoisomer, has been achieved by ether formation between a proline-derived chloroethylpyrrolidine and an enantiomerically enriched tertiary alcohol. The tertiary alcohol was formed from the carbamate derivative of α-methyl-p-chlorobenzyl alcohol by invertive aryl migration on lithiation. The (S,S)-stereochemistry of the product confirms the invertive nature of the rearrangement.
- Fournier, Anne M.,Brown, Robert A.,Farnaby, William,Miyatake-Ondozabal, Hideki,Clayden, Jonathan
-
supporting information; experimental part
p. 2222 - 2225
(2010/08/04)
-
- SUBSTITUTED BENZHYDRYLETHERS
-
Disclosed herein are substituted benzhydrylethers of Formula I, processes of preparation thereof, pharmaceutical compositions thereof, and methods of their use thereof.
- -
-
Page/Page column 34
(2009/08/18)
-
- ASYMMETRIC SYNTHESIS OF 1-METHYL-2-(2-HYDROXYETHYL)PYRROLIDINE
-
An asymmetric synthesis of 1-methyl-2-(2-hydroxyethyl)pyrrolidine based on optically active 1-phenylethylamine is described.
- Nikiforov, Theo,Stanchev, Stephan,Milenkov, Branimir,Dimitrov, Vladimir
-
p. 1825 - 1829
(2007/10/02)
-