- PROCESS FOR PREPARING DILTIAZEM USING A HETEROGENEOUS TRIFUNCTIONAL CATALYST
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The present invention comprises a simplified synthesis of (+)-diltiazem through IE-PdOsW wherein IE is ion-exchanger, catalyzed three-component coupling reaction and Fe3+-exchanged clay catalyzed ring opening of sulfite with 2-aminothiophenol followed by cyclization as key steps.
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- Process for preparing diltiazem using a heterogeneous trifunctional catalyst
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The present invention comprises a simplified synthesis of (+)-diltiazem through IE-PdOsW wherein IE is ion-exchanger, catalyzed three-component coupling reaction and Fe3+-exchanged clay catalyzed ring opening of sulfite with 2-aminothiophenol followed by cyclization as key steps.
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- Improved procedure for Julia-Colonna asymmetric epoxidation of α,β-unsaturated ketones: Total synthesis of diltiazem and Taxol side-chain
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Poly-L-leucine catalyses the asymmetric epoxidation of enones 1-6 efficiently in a non-aqueous medium to provide the epoxy ketones 7-12 (70-91% yield; 80 to ≥95% ee). The strategy was used to make diltiazem 16 and the Taxol side chain 23 in single enantiomer form.
- Adger, Brian M.,Barkley, James V.,Bergeron, Sophie,Cappi, Michael W.,Flowerdew, Benjamin E.,Jackson, Mark P.,McCague, Ray,Nugent, Thomas C.,Roberts, Stanley M.
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p. 3501 - 3507
(2007/10/03)
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- Process for the preparation of diltiazem
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(+)-Cis-3-(acetoxy)-5-[2-(dimethylamino)-ethyl]-2,3-dihydro-2-(4-methoxyphenyl)-1,5-benzothiazepin-4(5H)-one hydrochloride is prepared by N-alkylation of (+)-cis-3-hydroxy-2,3-dihydro-2-(4-methoxyphenyl)-1,5-benzothiazepin-4(5H)-one with dimethylaminoethyl chloride and K2 CO3 in toluene/water, addition of a solubilizing agent and in the presence of a phase-transfer catalyst, the toluene phase being directly subjected to the final O-- acetylation.
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- Process for the preparation of benzothiazepin-one derivatives
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The object of the invention is a process for the preparation of the trans(-) (2R,3S) diastereoisomer of the glycidic esters of general formula: STR1 wherein a chlorohydrin of general formula: STR2 is reacted with a strong organic base in a suitable solvent and at a temperature between -10° C. and room temperature. Another object of the invention is intermediate compounds cis(+) (2S,3S) 1,5-benzothiazepin-4-one.
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- Controlled release pharmaceutical preparation
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A controlled release pharmaceutical preparation comprising a core containing a medicinal compound and a coating layer containing a water-repellent salt and a water-insoluble and slightly water-permeable acrylic polymer having trimethylammoniumethyl group. Said preparation releases a medicinal compound in a sigmoid type dissolution pattern irrespective of the PH of a dissolution medium.
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- Some Applications of Isopropenyl Acetate to O-, N- and C-Acetylation
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New procedure for the preparation of drugs and drug intermediates (isosorbide-5-nitrate, diltiazem) and intermediates of potential drugs using isopropenyl acetate are described.
- Gizur, Tibor,Harsanyi, Kalman
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p. 2365 - 2371
(2007/10/02)
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- Process for the preparation of benzothiazepine derivatives
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The present invention relates to a process for the preparation of benzothiazepine derivatives of general formula I STR1 wherein R stands for hydrogen and acetyl or of acid addition salts thereof in which a corresponding compound of general formula II STR2 in which R has the same meaning as above is reacted with 2-(dimethylamino)-ethyl chloride in a biphasic system of water and a non-combustible aliphatic polychlorinated hydrocarbon solvent in the presence of calcium hydroxide or of barium hydroxide. The process is advantageously performed at a temperature between 15° and the refluxing temperature of the aliphatic polychlorinated hydrocarbon solvent. The process is optionally performed in the presence of a suitable quaternary ammonium halide. In the process the amount of calcium hydroxide or barium hydroxide is advantageously 1-3 moles per 1 mole of the compound of general formula II, the amount of aliphatic polychlorinated hydrocarbon solvent is advantageously 15-40 ml and that of water 3-10 ml per g of the compound of general formula II and the ratio aliphatic chlorinated hydrocarbon solvent:water is advantageously 2:1 to 10:1.
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