METHOD OF SEPARATING RACEMIC 1-(ISOPROPYLAMINO)-3-(1-NAPHTHYLOXY)-2-PROPANOL INTO ENANTIOMERS Russian patent published in 2005 - IPC

FIELD: special methods in organic synthesis.

SUBSTANCE: known drug: racemic 1-(isopropylamino)-3-(1-naphthyloxy)-2-propanol, briefly called propranolol, is converted into propranolol hydrofluoride, which is dissolved in ethanol at 55-70^оС to form concentrated solution. The latter is gradually cooled to 20-26^оС, after which is added seed of one of enantiomers, solution is stirred for 30-60 min, filtered non-racemic propranolol hydrofluoride enantiomer having the same configuration as the seed previously added. Racemic compound is added to mother liquor in amount compensating separated precipitate, mother liquor is heated at 55-70^оС to entirely dissolve added material and seed of the other enantiomer is added. Subsequent crystallization gives precipitate rich in the other enantiomer and process is several times repeated. Enantiomer purity is then raised by recrystallization. Non-racemic propranolol salts are finally converted into free propranolol enantiomers. Method of invention can be used in pharmaceutical practice.

EFFECT: enabled involvement method-assisted preparation of non-racemic propranolol.

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