Claims
- 1. A process for the preparation of a compound of formula (I) in optically active form with absolute configuration (R) or (S) whereY is an OR or NR1R2 group with R equal to hydrogen, C1-C10 alkyl or alkyl substituted with C6-C10 aryl, said aryl optionally carrying one or more C1-C4 alkyls; R1 and R2, equal or different from one another, are hydrogen, C1-C10 alkyl or alkyl substituted with C6-C10 aryl, said aryl optionally carrying one or more C1-C4 aryls or, taken together, form a 5-7 atom heterocyclic ring with the nitrogen atom; or Y is the residue of an esterified polyalcohol with at least one nitric acid equivalent; X− is the anion of a pharmaceutically acceptable organic or inorganic acid, or, if Y is an OH group, the formula (I) product may exist in the form of an inner salt of the formula (II) and their enantiomerically enriched mixtures, said process comprising treating a formula (III) compound with a nitrating agent causing an SN2 nucleophilic substitution reaction with substitution of the T group according to the following scheme: where T is an hydroxy group or T is a leaving group, X1−, equal to or different from X−, being included among the meanings illustrated above, to yield the formula (I) compound with the same absolute configuration as the formula (III) compound.
- 2. The process according to claim 1, in which said nitrating agents are selected from the group consisting of alkaline nitrates, alkaline-earth nitrates, silver nitrate, ammonium nitrate and tetra-alkylammonium nitrate.
- 3. The process according to claim 1, in which the T group is an OSO2Z group, where Z is C1-C10 alkyl, alkyl substituted with one or more halogen atoms, C6-C10 aryl, said aryl optionally being substituted with one or more halogen atoms, C1-C4 alkyl group, or C1-C4 alkoxy.
- 4. A process for the preparation of (R)-carnitine, comprising the following steps:a) treatment of a formula (III) enantiomer of configuration (R), of claim 1, with a nitrating agent whose mechanism of action involves an SN2 nucleophilic substitution reaction with substitution of the T group to yield the formula (I) compound with the opposite absolute configuration to the formula (III) compound; and b) treatment of the formula (I) compound with diluted bases.
- 5. A process for the preparation of (S)-carnitine, comprising the following steps:a) treatment of a formula (III) enantiomer of configuration (S), of claim 1, with a nitrating agent whose mechanism of action involves an SN2 nucleophilic substitution reaction with substitution of the T group to yield the formula (I) compound with the opposite absolute configuration to the formula (III) compound; and b) treatment of the formula (I) compound with diluted bases.
Priority Claims (1)
Number |
Date |
Country |
Kind |
RM99A0508 |
Aug 1999 |
IT |
|
Parent Case Info
This application is a continuation of PCT/IT00/00325, filed Jul. 31, 2000.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
3830931 |
De Felice |
Aug 1974 |
A |
5227513 |
Meul |
Jul 1993 |
A |
5532410 |
Giannessi et al. |
Jul 1996 |
A |
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Number |
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0 609 643 |
Aug 1994 |
EP |
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Continuations (1)
|
Number |
Date |
Country |
Parent |
PCT/IT00/00325 |
Jul 2000 |
US |
Child |
09/804270 |
|
US |