Pfizer Corporation

Bernard S Moore

Berkeley W Cue

Frank J Urban

Ronnie D Carroll

James R Tretter

Scraper

Process and intermediate useful in the preparation of optically active 3-formyltetrahydropyrans from racemic 3-formyltetrahydropyran.

Process and intermediates for optically active 3-formyltetrahydropyrans

Preparative method for 3S-(3-pyridylmethyl)-6-(2-quinolyl)methoxy-4S-chromanol via its salt with natural tartaric acid.

Optical resolution method for

Chiral sorbinil intermediates of the formula ##STR1## wherein R is hydrogen or benzyloxycarbonyl and Y is hydroxy or amino, processes therefor, and processes for the conversion thereof to sorbinil.

Processes and intermediates for sorbinil

S-6-fluoro-4-aminochroman-4-carboxylic acid derivatives useful as

6-Fluoro-4-chromanone can be regenerated from (R)-6-fluoro-4-ureidochroman-4-carboxylic acid, or from mixtures of (R)-6-fluoro-4-ureidochroman-4-carboxylic acid and its racemic modification, by oxidation with a permanganate, especially potassium permanganate. 6-Fluoro-4-chromanone is a chemical intermediate useful for preparing sorbinil, an aldose reductase inhibitor which can be used in clinical medicine for the control of the chronic complications of diabetes. (R)-6-Fluoro-4-ureidochroman-4-carboxylic acid and its racemic modification are by-products from the production of sorbinil from 6-fluoro-4-chromanone.

Regeneration of 6-fluoro-4-chromanone from

Sorbinil is obtained by cyclization of S-6-fluoro-4-ureidochromane-4-carboxylic acid, which is in turn obtained by resolution of racemic 6-fluoro-4-ureidochroman-4-carboxylic acid via diasteromeric salts with either D-(+)-(1-phenethyl)amine or L-(-)-ephedrine.

Sorbinil by optical resolution of precursor

A process for the preparation of penicillanic acid 1,1-dioxide and esters thereof readily hydrolyzable in vivo, which comprises oxidation of a 6-halopenicillanic acid, or an ester thereof readily hydrolyzable in vivo, to the corresponding 6-halopenicillanic acid 1,1-dioxide or ester thereof, followed by dehalogenation (e.g. by hydrogenolysis). Certain of the 6-halopenicillanic acid 1,1-dioxides and esters thereof readily hydrolyzable in vivo are novel intermediates. Penicillanic acid 1,1-dioxide, and esters thereof readily hydrolyzable in vivo are known compounds which are beta-lactamase inhibitors and which enhance the effectiveness of certain beta-lactam antibiotics (e.g. the penicillins) in the treatment of bacterial infections in mammals, particularly humans.

6-Alpha-halopenicillanic acid 1,1-dioxides

5-Phenyl-2S-pentanol is synthesized stereospecifically from S ethyl lactate. The method provides easily purified 5-phenyl-2S-pentanol useful in the synthesis of central nervous system active (CNS) agents such as levonantradol.

Stereospecific synthesis of 5-phenyl-2S-pentanol

Resolution of racemic 5-phenyl-2-pentanol via the hemiphthalate ester, followed by diastereomer salt formation with (+)-brucine, separation of the brucine salt of (S)-5-phenyl-2-pentanol hemiphthalate and recovery of the (S)-alcohol therefrom. The (S)-5-phenyl-2-pentanol is a valuable intermediate for organic synthesis.

Resolution of racemic 5-phenyl-2-pentanol

The maleic acid salt of 2-phenyl-6-(1-hydroxy-2-t-butylaminoethyl)-4H-pyrido[3,2-d]-1,3-dioxin, its preparation and use as an intermediate for making 2-hydroxymethyl-3-hydroxy-6-(1-hydroxy-2-t-butylaminoethyl)pyridine, an effective bronchodilator.

Growing community of inventors

Waterford, CT, United States of America

Bernard S Moore