72376-78-4

Upstream product

• 479-18-5 diprophylline 
• 58-55-9 theophylline 
• 23146-07-8 1,3-dimethyl-7-(oxiran-2-ylmethyl)-3,7-dihydro-1H-purine-2,6-dione 
• 3880-32-8 7-(3-Chlor-2-hydroxy-propyl)-theophyllin 
• 81660-14-2 1-chloro-3-(1,3-dimethyl-2,6-dioxo-1,2,3,6-tetrahydro-7H-purin-7-yl)propan-2-yl acetate 

Relevant academic research and scientific papers

Chemoenzymatic synthesis of enantiomerically enriched diprophylline and xanthinol nicotinate

A concise chemoenzymatic route toward enantiomerically enriched active pharmaceutical ingredients (API) – diprophylline and xanthinol nicotinate – is reported for the first time. The decisive step is an enantioselective lipase-mediated methanolysis of racemic chlorohydrin-synthon acetate, namely 1-chloro-3-(1,3-dimethyl-2,6-dioxo-1,2,3,6-tetrahydro-7H-purin-7-yl)propan-2-yl acetate, performed under kinetically-controlled conditions on a preparative 500 mg-scale. The best results in terms of reaction enantioselectivity (E = 14) were obtained for the enantiomers resolution performed with lipase type B from Candida antarctica immobilized on acrylic resin (CAL-B, Novozym 435) suspended in homophasic acetonitrile-methanol mixture. The elaborated biocatalytic system furnished the key chlorohydrin intermediate (in 71% ee and 38% yield), which was then smoothly converted into enantioenriched active agents: (R)-(–)-diprophylline (57% ee) and (S)-(+)-xanthinol nicotinate (65% ee). To support the assignment of absolute configurations of EKR-products as well as to confirm the stereochemical outcome of the remaining reaction steps, docking studies toward the prediction of enantiomers binding selectivity in CAL-B active site as well as the respective chemical correlations with enantiomerically enriched analytical standards obtained from commercially available (R)-(–)-epichlorohydrin, were applied. In addition, single-crystal X-ray diffraction (XRD) analyses were performed for the synthesized optically active APIs furnishing by this manner a first crystal structures of nicotinic acid salt of xanthinol.

Separating agent for optical isomers

A separating agent for optical isomers that uses a polysaccharide derivative provided by replacing all or a portion of the hydrogen atoms on the hydroxyl groups present in a polysaccharide with two specific atomic groups that act on optical isomers targeted for separation in an optical resolution, wherein the sum of the average introduction ratios of specific terminal substituents in these atomic groups is greater than 3.0 per monosaccharide unit.