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MXPA98007266A - Treo-metilfenid resolution - Google Patents

Treo-metilfenid resolution

Info

Publication number
MXPA98007266A
MXPA98007266A MXPA/A/1998/007266A MX9807266A MXPA98007266A MX PA98007266 A MXPA98007266 A MX PA98007266A MX 9807266 A MX9807266 A MX 9807266A MX PA98007266 A MXPA98007266 A MX PA98007266A
Authority
MX
Mexico
Prior art keywords
resolution
methylphenidate
threo
treo
metilfenid
Prior art date
Application number
MXPA/A/1998/007266A
Other languages
Spanish (es)
Other versions
MX202728B (en
MX9807266A (en
Inventor
Shahriari Zavareh Hooshang
Original Assignee
Medeva Europe Limited
Shahriari Zavareh Hooshang
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from GBGB9604943.2A external-priority patent/GB9604943D0/en
Application filed by Medeva Europe Limited, Shahriari Zavareh Hooshang filed Critical Medeva Europe Limited
Publication of MX9807266A publication Critical patent/MX9807266A/es
Publication of MXPA98007266A publication Critical patent/MXPA98007266A/en
Publication of MX202728B publication Critical patent/MX202728B/es

Links

Abstract

A method for preparing the substantially individual enantiomer d-threo-methylphenidate is described, proceeds through means of a classical salt resolution using (-) - methoxyacetic acid.

Description

TREO-METHYLPHENIDATE RESOLUTION DESCRIPTION OF THE INVENTION This invention relates to the resolution of threo-methylphenidate through the crystallization of diastereomeric salts. The methylphenidate was first prepared as a mixture of ether and threo racemates. US-A-2957880 describes studies on the two racemic mixtures, which reveal that the therapeutic activity resides in. the threo diastereomer. Resolution of treormethylphenidate can be achieved by using the expensive resolution agent, with 1, 1'-diacid phosphate, 2'-2'-biphenyl, a first procedure reported by Patric et al (The Journal of Eharmacology and Experimental Therapeutics, 241: 152- 158 (1987)), and subsequently used by other workers in the field (eg, Aoyama et al., Journal of Chromatography, 494: 420 (1989)). This was perceived as a more efficient process than the method described in US-A2957880, where the corresponding amide of er-methyl-methylphenidate (ie, R-CONR, instead of R-C0N-Me) was resolved with tartaric acid , before hydrolysis with amide and equilibrium in the benzylic center, followed by the esterification of the resulting acid.
An improved resolution procedure is described in PCT / GB97 / 00185. Said resolution can be combined, with the racemization described in PCT / GB97 / 00281_. This invention is based on the discovery that racemic threo-methylphenidate can be resolved using very expensive (-) -methoxyacetic acid. The process of this invention can be carried out under conditions that are generally known to those skilled in the art of classical salt resolution procedures. For example, a mixture of treo-. Free base methylphenidate and one molar equivalent of _ (-) - methoxyacetyl acid in an inert organic solvent is heated and allowed to cool; the resulting precipitate is filtered, washed with an appropriate solvent and dried to directly yield a salt rich in 98% ee of d-threo-methylphenidate. This is a huge improvement in the method of the literature using phosphate 2-2 '- 1-1'-hydrophilic acid, described by Patpck et al., Supra, where the first crystallization gave a salt corresponding to 85-90 ^ of the . material, and additional recrystallization of this material was necessary to increase the ee., to 95-97%. The last level of optical purity was achieved in the present invention in a crystallization, with a higher total yield. The method of this invention, therefore, is more efficient and more economical than that described by Patrick et al.
The following example illustrates the resolution of threo-methylphenidate using [-] -methoxyacetic acid. EXAMPLE dJ-Threo-methylphenidate (1.0 g, 3.7 mmol) was suspended in water (20 ml) and treated with a caustic solution. The released free base was extracted with MTBE (3x25ml), dried over MgSO (, and evaporated to a light oil.) This was dissolved in IPA (15 ml) and heated to 60 ° C, (-) - acid was added. methoxyacetic (0.79 g, 3.79 mmole) in IPA (5 ml) The heating was continued for a further 30 minutes and the mixture was gradually cooled to 10 ° C. The resulting white crystalline product was filtered, washed with cold IPA and dried (0.85 g, 47% by weight, corresponding to 98? ee of d-threo-methylphenidate, as determined by chiral CLAP after salt distillation).

Claims (1)

1. A process for preparing the substantially individual enantiomer d-threo-methylphenidate which proceeds through a classical salt resolution using acid. { -) -methoxyacetic.
MXPA/A/1998/007266A 1996-03-08 1998-09-07 Treo-metilfenid resolution MXPA98007266A (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
GBGB9604943.2A GB9604943D0 (en) 1996-03-08 1996-03-08 Resolution
GB9604943.2 1996-03-08
US1698696P 1996-05-07 1996-05-07
US016986 1996-05-07

Publications (3)

Publication Number Publication Date
MX9807266A MX9807266A (en) 1999-08-31
MXPA98007266A true MXPA98007266A (en) 1999-10-14
MX202728B MX202728B (en) 2001-06-29

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