Method for splitting 1-amino-alkan-2-ol compounds

Details Method for splitting 1-amino-alkan-2-ol compounds Method for splitting 1-amino-alkan-2-ol compounds

1999-05-28

2001-11-13

Kumar, Shailendra (Department: 1621)

Organic compounds -- part of the class 532-570 series

Organic compounds

Amino nitrogen containing

C564S302000, C564S505000

Reexamination Certificate

active

06316671

ABSTRACT:

FIELD OF THE INVENTION
This invention relates to a method of splitting 1-amino-alkan-2-ol compounds of general formula:
in which the group R can represent a wide variety of linear, branched or cyclic alkyl groups, comprising up to about 20 to 25 carbon atoms and preferably 1 to 15 carbon atoms. These groups can possibly have one or more double bonds, one or more hetero-atoms such as oxygen or sulfur so long as these are to be found separated from the asymmetric carbon atom by at least one carbon link and do not destroy the aliphatic nature of the group R. These groups can also be substituted by one or more halogen atoms such as chlorine or lower alkoxy groups such as methoxy or ethoxy groups.
BACKGROUND
From an industrial point of view, the resolution of (±) chiral compounds is in most cases an advantageous alternative to the asymmetric synthesis of one of the enantiomers.
In the case of compounds of formula (I), resolution through biased crystallization can be carried out by several methods when R is an aryl group (1, 2). Syntheses of compounds of formula (I) in which R is an alkyl group, from chiral reactants have also been described (3 to 11). These syntheses do not represent a general method but are specified on a case by case basis and until now, resolutions based on a diastereoisomeric crystallization or a preferential crystallization have not resulted in a satisfactory outcome (12 to 18).
SUMMARY OF THE INVENTION
This invention is aimed precisely at providing a method of resolving salts by a selective crystallization, easy to implement, reproducible and permitting access to the two enantiomers with high enantiomeric purity, possibly greater than 99%.
This goal is achieved thanks to the formation of salts of 1-amino-alkan-2-ol salts corresponding to the following general formula:
{X
−
, RCHOH—CH
2
—NH
3
+
}
with X producing pairs of diastereoisomers of different solubilities, or with X producing a conglomerate.
More particularly, the invention is based on the use of a simple and very selective chiral agent which also has the advantage of being easy to prepare and easy to recover on completion of the method. This chiral agent is one of the enantiomers R or S of N-tosyl-leucine.
Hence, when X, in the formula above is one of the enantiomers R or S of N-tosyl-leucine, pairs of diastereoisomers with different solubilities are produced.
According to another aspect of the invention, when X, in the formula above, is trans-cinnamic acid, in certain cases, a conglomerate is produced.


REFERENCES:
patent: 3116332 (1963-12-01), Sullivan et al.
patent: 5723667 (1998-03-01), Drauz et al.
patent: 5986135 (1999-11-01), Pfrengle et al.
Drauz, Karlheinz et al, Chem. Eur J., 1(8), 538-540, 1995.*
Leonard et al, Chemical Abstract, vol. 115, No. 9. 91743, 1991.

Affiliated with

Also associated with

Rating

Method for splitting 1-amino-alkan-2-ol compounds does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method for splitting 1-amino-alkan-2-ol compounds, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for splitting 1-amino-alkan-2-ol compounds will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2597983