149965-40-2Relevant articles and documents
Continuous-Flow Amide and Ester Reductions Using Neat Borane Dimethylsulfide Complex
?tv?s, Sándor B.,Kappe, C. Oliver
, p. 1800 - 1807 (2020/02/27)
Reductions of amides and esters are of critical importance in synthetic chemistry, and there are numerous protocols for executing these transformations employing traditional batch conditions. Notably, strategies based on flow chemistry, especially for amide reductions, are much less explored. Herein, a simple process was developed in which neat borane dimethylsulfide complex (BH3?DMS) was used to reduce various esters and amides under continuous-flow conditions. Taking advantage of the solvent-free nature of the commercially available borane reagent, high substrate concentrations were realized, allowing outstanding productivity and a significant reduction in E-factors. In addition, with carefully optimized short residence times, the corresponding alcohols and amines were obtained in high selectivity and high yields. The synthetic utility of the inexpensive and easily implemented flow protocol was further corroborated by multigram-scale syntheses of pharmaceutically relevant products. Owing to its beneficial features, including low solvent and reducing agent consumption, high selectivity, simplicity, and inherent scalability, the present process demonstrates fewer environmental concerns than most typical batch reductions using metal hydrides as reducing agents.
Dapagliflozin preparation method
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Paragraph 0033; 0034; 0046; 0047, (2018/04/01)
The invention relates to a Dapagliflozin preparation method, which comprises the following steps: using 2-chlorobenzaldehyde as a starting material, carrying out bromination, reducing, chlorinating tosynthesize 5-bromo-2-chlorobenzyl chloride, carrying out Friedel-Crafts alkylation reaction between 5-bromo-2-chlorobenzyl chloride and phenetole to synthesize 5-bromo-2-chloro-4'-ethyoxyldiphenylmethane, conducting condensation between 5-bromo-2-chloro-4'-ethyoxyldiphenylmethane and 2,3,4,6-tetra-O-trimethylsilyl-D-glucolactone, carrying out trimethylsilyl deprotection, conducting etherification, and reducing for demethylation to obtain a hypoglycemic drug Dapagliflozin. The invention has the following advantages: according to the Dapagliflozin preparation method, 2-chlorobenzaldehyde, whichis used as a starting material, is cheaper and easily available in comparison with 5-bromo-2-chlorobenzoic acid, and the technology is easy for industrialization; during the synthetic process, no rawmaterials which cause severe toxicity will be used and furthermore there is no dangerous process; the synthetic route is short and novel and the operation is simple; and through the synthetic route,purity of the final product can be raised, and the purity can reach 99% and above.
3-OXO-1,4-DIAZEPINYLE COMPOUNDS AS NRF2 ACTIVATORS
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Page/Page column 96, (2018/07/05)
The present invention relates to bisaryl lactam compounds, methods of making them, pharmaceutical compositions containing them and their use as NRF2 activators. In particular, the compounds of this invention include a compound of Formula (I):
