Separation of an enantiomer mixture of (R)- and (S)-3-amino-1-butanol

摘要

The present invention relates to a process for separating an enantiomer mixture of (R)- and (S)-3-amino-1-butanol optionally protected on the oxygen atom, and to a process for preparing essentially enantiomerically pure (R)-3-amino-1-butanol which optionally bears a protecting group on the oxygen atom.

主权项

1. A process for separating an enantiomer mixture of (R)- and (S)-3-amino- 1 -butanol optionally protected on the oxygen atom, comprising the following steps:
(i) reacting an enantiomer mixture of the compounds of the formulae I-R and I-S wherein R1 is hydrogen or a protecting group selected from C1-C4-alkyl with (S)- or (R)-mandelic acid and an acid different from this (S)- or (R)-mandelic acid used (ii) removing and isolating the (S)- or (R)-mandelic salt of the compound of the formula I-R formed in step (i); (iii) optionally purifying the (S)- or (R)-mandelic salt of the compound of the formula I-R isolated in step (ii); (iv) releasing the compound of the formula I-R from the (S)- or (R)-mandelic salt thereof and if desired deprotecting the compound of the formula I-R in which R1 is not hydrogen to obtain (R)-3-amino-1-butanol; and (v) optionally releasing the enriched compound of the formula I-S and optionally deprotecting the compound of the formula I-S wherein R1 is not hydrogen to obtain enriched (S)-3-amino-1-butanol;wherein the compound of the formula I-R is released from the (S)- or (R)-mandelic salt thereof in step (iv) by reacting the (S)- or (R)-mandelic salt of the compound of the formula I-R obtained in step (ii) or (iii) with a base selected from alkali metal C1-C4-alkoxides in a solvent which possesses a boiling point at least 10° C. higher than 3-amino-1-butanol and is selected from organic amines having a melting point of at most 50° C. and a boiling point of at least 180° C.