3639-23-4Relevant academic research and scientific papers
METHOD FOR SYNTHESIZING ENANIOMERICALLY PURE N-(PYRIDIN-4-YL)-2-HYDROXY-ALKYLAMIDE DERIVATIVES
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Paragraph 0231, (2019/01/25)
The present invention relates to a novel process for preparing enantiomerically pure compounds of N-(pyrid-4-yl)-2-hydroxyalkylamide type corresponding to the general formula (C) below: and also to processes for preparing the reaction intermediates used i
Process Development and Crystallization in Oiling-Out System of a Novel Topical Antiandrogen
Daver, Sébastien,Rodeville, Nicolas,Pineau, Francois,Arlabosse, Jean-Marie,Moureou, Christine,Muller, Franck,Pierre, Romain,Bouquet, Karinne,Dumais, Laurence,Boiteau, Jean-Guy,Cardinaud, Isabelle
, p. 231 - 240 (2017/02/26)
An efficient route to (S)-N-(2-bromo-6-methoxypyridin-4-yl)-2-hydroxy-2,4-dimethylpentanamide 1, a new topical antiandrogen, is described. The target compound has been manufactured on kilogram scale with an overall yield of 25% (HPLC purity 98.8% and >99% ee) from citrazinic acid. The key amide coupling between aminopyridine 4 and α-hydroxy-acid 6 was performed using a temporary protecting group to facilitate the acyl chloride formation. Aminopyridine 4 was manufactured from commercially available citrazinic acid via dibromide formation using phosphorus(V) oxybromide followed by mono SNAr reaction with sodium methoxide and a final Hofmann rearrangement. Enantiopure α-hydroxy-acid 6 was obtained using an enantioselective cyanosilylation followed by salt resolution with (S)-α-methyl benzylamine. The absolute configuration of compound 1 was determined with anomalous scattering and the final crystallization of API was performed after seeding a liquid-liquid mixture below the monotectic temperature and afforded a crystalline powder presenting a "desert rose" shape clusters.
Catalytic asymmetric synthesis of dihydrofurans and cyclopentenols with tertiary stereocenters
Wu, Zhongtao,Madduri, Ashoka V. R.,Harutyunyan, Syuzanna R.,Minnaard, Adriaan J.
, p. 575 - 582 (2014/02/14)
A new asymmetric synthesis of dihydrofurans and cyclopentenols has been developed and is based on the copper-catalyzed 1,2-addition of Grignard reagents to enones in combination with Sonogashira coupling/cyclization or ring-closing metathesis. By this approach, dihydrofurans with an oxygen-containing tertiary stereocenter and chiral tertiary cyclopentenols are efficiently prepared. The absolute stereochemistry of the products has been established. The copper-catalyzed 1,2-addition of Grignard reagents to enones, combined with Sonogashira coupling/cyclization or ring-closing metathesis, provides a new asymmetric synthesis of dihydrofurans and cyclopentenols. Two different kinds of dihydrofurans are obtained with medium-to-high enantioselectivities. Copyright
Enzyme-catalyzed synthesis of (R)-ketone-cyanohydrins and their hydrolysis to (R)-α-hydroxy-α-methyl-carboxylic acids
Effenberger,Horsch,Weingart,Ziegler,Kuhner
, p. 2605 - 2608 (2007/10/02)
(R)-Ketone-cyanohydrins (R)-2 are obtained with high enantioselectivity from aliphatic ketones 1 and HCN in organic solvents using (R)-oxynitrilase ( EC 4.1.2.10) as catalyst. Acid catalyzed hydrolysis of the cyanohydrins (R)-2 affords the corresponding (R)-α-hydroxy-α-methyl-carboxylic acids (R)-3 without measurable racemization.
