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US 2003/0153771 A1Published application
Large scale synthesis of optically pure aziridines
OwnerHartmuth C. Kolb, Ramanaiah C. Kanamarlapudi +2inventors
InventorsHartmuth C. Kolb, Ramanaiah C. Kanamarlapudi, Paul F. Richardson, Gaznabi Khan
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Abstract
Disclosed is an efficient, inexpensive method for the preparation of chiral aziridines on a large scale.
Claims21
A method for preparing a chiral aziridine comprising:
- (a) treating an α-amino alcohol with a sulfuric acid to form a sulfate ester;
- and
- (b) cyclizing the sulfate ester in the presence of base to form the chiral aziridine.
A method of preparing a chiral aziridine of the formula
- 36
- wherein
- is a bond representing either (S) or (R) configuration with respect to the carbon atom to which it is attached;
- R is hydrogen, or
- lower alkyl optionally substituted with one, two, three or four groups independently selected from halogen, aryl, cycloalkyl, heteroaryl, lower alkoxy, —C(O)-alkyl, —C(O)NH-alkyl, C(O)N-dialkyl, nitro, alkenyl or alkynyl, or
- aryl or heteroaryl optionally substituted with one, two, three or four groups independently selected from halogen, lower alkyl, lower alkoxy, —C(O)— alkyl, —C(O)NH-alkyl, C(O)N-dialkyl, nitro, alkenyl or alkynyl;
- and
- R1 is hydrogen or lower alkyl,
- the method comprising
- (a) treating an α-amino alcohol of the formula
- 37
- with a sulfuric acid to form a sulfate of the formula
- 38
- (b) heating the sulfate under reduced pressure to form a sulfate ester of the formula
- 39
- (c) cyclizing the sulfate ester in the presence of base to form the chiral aziridine.
13 more elements
Dependencies are inferred from the claim text.