Process for the preparation of optically active amines
AssigneeBayer Aktiengesellschaft
InventorsUwe Stelzer, Claus Dreisbach
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Abstract
Process for preparing optically (S) and (R) active amines of the formula (I*) comprising reacting racemic amines corresponding to formula (I*) with esters of the formula: in the presence of lipase from Candida antarctica, and separating the (S)-amine directly from the resulting mixture, and separating the (R)-amine indirectly from the resulting mixture by reacting the acylated (R)-amine therein, which has the formula: with acid or base, wherein all the formula above, the variables are as defined herein. Certain precursors of the formula (III) are also disclosed.
Claims4
A process for preparing an optically active amine of the formula:
- in which
- R represents a substituted phenyl group of the formula:
- in which
- R4 and R6 are hydrogen and R5 is chlorine, fluorine, methyl or methoxy, and
- m represents the numbers 0, 1 or 2, which process comprises
- a) reacting in a first step a racemic amine of the formula:
- in which
- R and m are each defined as above,
- with an ester of the formula
- in which
- R1 represents methyl, ethyl, n-propyl, n-butyl, chloromethyl, 2-chloroethyl, 2-fluoroethyl or 2,2,2-trifluoroethyl,
- R2 represents hydrogen
- X represents oxygen, and
- n represents the numbers 1 or 2, in the presence of 10,000 to 112,000 units per mole of racemic amine of lipase from Candida antarctica and, in the presence of a diluent,
- b) separating in a second step the resulting mixture of (S)-amine of the formula:
- in which
- R and m are each as defined above,
- and acylated (R)-amine of the formula:
- in which
- R, R2, X, m and n are each defined above, and
- c) setting free, in a third step, the (R)-amine of the formula:
- in which
- R and m are each as defined above, by treatment of the acylated (R)-amine of the formula (III) with an acid or base in the presence of a diluent.
Dependencies are inferred from the claim text.