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US 2002/0165269 A1Published application
Process for preparing optically active dihydropyrones
AssigneeBoehringer Ingelheim Pharma GmbH & Co. KG
InventorsMarkus Sauter, Burkhard Jaeger
Life of this patent
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Abstract
The invention relates to a new process for preparing optically active dihydropyrones, new intermediate products which may be obtained by this synthesis, and their use as starting compounds in the preparation of pharmaceutically active compounds.
Claims11
1) A process for preparing a compound of formula 1
- 11
- optionally in the form of the tautomers thereof,
- wherein
- R1 and R2 independently of one another denote hydrogen or a group selected from C1-C4-alkyl, C3-C8-cycloalkyl, C6-C10-aryl and —C1C4-alkylene-C6-C10-aryl, which may optionally be mono-, di- or trisubstituted by one or more groups selected from hydroxy, halogen, C1-C4-alkoxy and CF3, with the proviso that R1 and R2 cannot simultaneously have the same meaning, comprising:
- wherein a first step reacting a compound of formula 1-rac
- 12
- wherein R1 and R2 may have the meanings given in this claim, in a suitable solvent with one or more chiral aminoalcohol of formula 4
- 13
- wherein
- R3, R3′, R4 and R4′ which may be identical or different denote hydrogen or a group selected from C1-C4-alkyl, C3-C8-cycloalkyl, C6-C10-aryl and —C1-C4—alkylene-C6-C10-aryl, which may optionally be mono-, di- or trisubstituted by one or more groups selected from hydroxy, halogen, C1-C4-alkoxy, —S—C1-C4—alkyl, —SO2-C1-C4-alkyl, NO2 and CF3, with the proviso that if R3 and R3′ have the same meaning, the groups R4 and R4′ cannot have the same meaning, and
- with the proviso that if R4 and R4′ have the same meaning, the groups R3 and R3′ cannot have the same meaning,
- to form a salt of formula 1-salt
- 14
- wherein the groups R1, R2, R3, R3′, R4 and R4′ may have the meanings given hereinbefore, isolating the resulting crystalline compound 1-salt and subsequently isolating the target compound of the formula 1 therefrom.
11 more elements
7) A compound of formula 1-salt
- 15
- wherein
- R1 and R2 independently of one another denote hydrogen or a group selected from C1-C4-alkyl, C3-C8-cycloalkyl, C6-C10-aryl and —C1-C4-alkylene-C6-C10-aryl, which may optionally be mono-, di- or trisubstituted by one or more groups selected from hydroxy, halogen, C1-C4-alkoxy and CF3;
- R3, R3′, R4 and R4′ which may be identical or different denote hydrogen or a group selected from C1-C4-alkyl, C3-C8-cycloalkyl, C6-C10-aryl and —C1-C4-alkylene-C6-C10-aryl, which may optionally be mono-, di- or trisubstituted by one or more groups selected from hydroxy, halogen, C1-C4-alkoxy, —S—C1-C4-alkyl, —SO2-C1-C4-alkyl, NO2 and CF3, optionally in the form of the tautomers thereof,
- with the proviso that R1 and R2 cannot simultaneously have the same meaning,
- with the proviso that if R3 and R3′ have the same meaning, the groups R4 and R4′ cannot have the same meaning, and
- with the proviso that if R4 and R4′ have the same meaning, the groups R3 and R3′ cannot have the same meaning.
4 more elements
Dependencies are inferred from the claim text.