- Preparation method of leverbuterol and its salt
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The invention provides a method for cheap and effective preparation of leverbuterol in industry. The method consists of: taking protected 4-hydroxy-3-hydroxymethyl acetophenone as the raw material to react with bromine to generate acyl or alkyl protected 4-hydroxy-3-hydroxymethyl bromoacetophenone, under in the presence of (1R, 2S)-(+)-indanol as a catalyst, using borane to conduct chiral reduction on carbonyl in the structural formula to obtain R configuration acyl or alkyl protected 4-hydroxy-3-hydroxymethyl alpha bromo phenethyl alcohol, then carrying out reaction with tert-butylamine to generate acyl or alkyl protected 4-hydroxy-3-hydroxymethyl phenylaminoethanol, and finally removing the acyl protecting group to obtain leverbuterol free alkali, and letting the free alkali and acid form a salt. The finished product has optical purity up to 99.9%, and no other chiral resolution way is needed for purification.
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Paragraph 0041; 0055; 0056; 0057; 0058; 0059; 0060
(2017/06/02)
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- PROCESS FOR THE PREPARATION OF OPTICALLY PURE R (-) SALBUTAMOL AND ITS PHARMACEUTICALLY ACCEPTABLE SALTS
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A process for the preparation of optically pure R (?) salbutamol of formula (6) and its pharmaceutically acceptable salts by using a (+) 4-nitro tartranilic acid as the resolving agent and a binary solvent system comprising alkyl acetate and C1 /sub
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Page/Page column 4-5
(2010/08/18)
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- A PROCESS FOR THE PREPARATION OF OPTICALLY PURE R (-) SALBUTAMOL AND ITS PHARMACEUTICALLY ACCEPTABLE SALTS
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A process for the preparation of optically pure R (-) salbutamol of formula (6) and its pharmaceutically acceptable salts by using a (+) 4-nitro tartranilic acid as the resolving agent and a binary solvent system comprising alkyl acetate and C1 to C4 branched or normal chain alcohol for dissolution of the racemic mixture and resolving agent and purification of the 4-nitro tartranilic acid salt of R (-) salbutamol. 4-nitro tartranilic acid salt of R (-) salbutamol is converted into formic acid salt of R(-) 4-benzyl salbutamol followed by basification and debenzylation to form optically pure R(-) salbutamol. Optically pure (R) -salbutamol is obtained in good yield and high purity. The optically pure R(-) salbutamol is optionally converted into pharmaceutically acceptable salts.
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Page/Page column 10
(2008/06/13)
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