160982-10-5Relevant articles and documents
Thiophene sulfonaide breene assists the amine process for the preparation of intermediates
-
Paragraph 0026; 0028, (2017/02/24)
The invention belongs to the technical field of pharmaceutical chemicals, in particular relates to a method for preparing an intermediate thiophene sulfonamide of brinzolamide and is applicable to industrial production. The method comprises the following steps: dissolving thiophene benzyl sulfide in a proper solvent, adding glacial acetic acid and water, controlling the temperature to 0-15 DEG C, adding trichloroisocyanuric acid in batches in 20-40 minutes, reacting at the constant temperature until the raw materials disappear, performing vacuum concentration in a water bath at the temperature of 30-50 DEG C to remove the solvent, adding ethyl acetate petroleum ether solution with the mass concentration of ethyl acetate being 25%, stirring, filtering, evaporating the filtrate under reduced pressure, thereby obtaining thiophenesulfonyl chloride; controlling the temperature to 0-15 DEG C, diluting thiophenesulfonyl chloride by ethyl acetate, dropwise adding a dilution into ammonium hydroxide or a water solution of amine, stirring and reacting until the raw materials disappear, filtering, washing, drying the solids, and obtaining the thiophene sulfonamide. The product obtained by using the method is high in yield, simple and convenient in operation, low in cost and mild in reaction conditions and is suitable for large-scale production.
Enantioselective synthesis of brinzolamide (AL-4862), a new topical carbonic anhydrase inhibitor. The "DCAT Route" to thiophenesulfonamides
Conrow, Raymond E.,Dean, W. Dennis,Zinke, Paul W.,Deason, Michael E.,Sproull, Steven J.,Dantanarayana, Anura P.,DuPriest, Mark T.
, p. 114 - 120 (2013/09/08)
A large scale synthesis of the topical carbonic anhydrase inhibitors AL-4623A (13a-HCl) and AL-4862 (13b) from 3-acetyl-2,5-dichlorothiophene ("DCAT", 1) is described. Reaction of 1 with NaSBn gave thioether 2, which was converted via sulfenyl chloride 3 and sulfenamide 5 to sulfonamide 6. Bromination of 6 gave bromo ketone 7, which upon reduction with (+)-B-chlorodiisopinocampheylborane and cyclization of the resulting bromohydrin produced S thieno[3,2-e]-1,2-thiazine 8a (96% ee) after chromatography. Treatment of 8a in THF with -BuLi at -70 °C resulted in Li-Cl exchange. Reaction of the thienyllithium with SO2 and hydroxylamine O-sulfonic acid afforded bis-sulfonamide 11a. Protection of lia as the acetimidate 12a, followed by tosylation and animation, gave R amine 13a. The synthesis of 13b proceeded via primary sulfonamide 16, which was brominated, reduced, and cyclized to give S thieno[3,2-e]-1,2-thiazine 18 (>98% ee). By virtue of the ionizable NH, 18 was separable from reduction byproducts by base extraction. Alkylation of 18 with 3-bromopropyl methyl ether afforded 8b, which was converted as above, via lib, to AL-4862 (13b). These procedures provided multihundred gram lots of 13a and 13b.
Preparation of carbonic anhydrase inhibitors
-
, (2008/06/13)
A process for synthesizing carbonic anhydrase inhibitors is disclosed.
