138890-50-3Relevant articles and documents
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 (1999)
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 methods of brinzolamide and an intermediate thereof
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Paragraph 0111-0139; 0140-0167; 0168-0192, (2018/03/24)
The invention discloses preparation methods of brinzolamide and an intermediate thereof. The preparation method of the brinzolamide intermediate represented by a compound C comprises: carrying out a condensation reaction on a compound B and an orthoester-based compound at a temperature of 70-80 DEG C in an organic solvent in the presence of tertiary amine under an anhydrous condition, wherein theorthoester-based compound is one or a plurality of materials selected from trimethyl orthoacetate, triethyl orthoacetate and trimethyl orthobenzoate. According to the present invention, the condensation reaction is performed by using the tertiary amine as the catalyst, such that the reaction time for the amino protection is substantially shortened, the consumption of the protection reagent is reduced, the reaction temperature is reduced, the yield and the purity of the product are improved, the acid consumption and the alkali consumption during the post-treatment are reduced, the residue on ignition of the product is reduced, the operation is simplified, and the method is suitable for industrial production. The formulas B and C are defined in the specification.
PHARMACEUTICALLY ACCEPTABLE SALT OF BRINZOLAMIDE AND COMPOSITION THEREOF
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Page/Page column 7; 9, (2013/08/15)
The present invention discloses the pharmaceutically acceptable salt of Brinzolamide as Brinzolamide maleate, process for the preparation of the Brinzolamide maleate, its polymorph and composition thereof.