- Method for preparing dorzolamide hydrochloride and method for purifying intermediate
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The invention relates to a method for preparing dorzolamide hydrochloride and a method for purifying an intermediate. The method for preparing the dorzolamide hydrochloride comprises the following steps: carrying out crystallization treatment on an ester solution of a compound ((4S, 6R-trans)-4-ethylamino-5, 6-dihydro-6-methyl-4H-thieno [2, 3-b] thiapyran-2-sulfonamide-7, 7-dioxide) as shown in the formula D15 of an intermediate to obtain a purified compound as shown in the formula D15; and reacting the compound as shown in the formula D15 with hydrochloric acid to obtain the dorzolamide hydrochloride. The synthesis process is shortened, so that the production time is saved, the efficiency is improved, and the cost is reduced.
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Paragraph 0060-0104
(2021/08/28)
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- Chiral synthesis method of dorzolamide hydrochloride
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The invention relates to a chiral synthesis method of dorzolamide hydrochloride, which comprises the following steps: (1) by taking a compound I that is (6S)-4-carbonyl-5,6-dihydro-4H-6-methyl-thieno[2,3b] thiopyran-2-sulfonamide-7,7-dioxide as an initial raw material, carrying out imidization reaction on the initial raw material and ethylamine to obtain a compound II that is (6S)-4-ethyl imino-5,6-dihydro-4H-6-methyl-thieno[2, 3b]thiopyran-2-sulfonamide-7,7-dioxide; (2) carrying out asymmetric hydrogenation reaction on the compound II obtained in the step (1), a catalyst and a chiral ligand (R)-(+)-1,1'-binaphthyl-2'-isopropoxy-2-diphenylphosphine to obtain a compound III that is dorzolamide; and (3) mixing the compound III obtained in the step (2) with hydrochloric acid, acidifying, washing and drying to obtain a compound IV, namely dorzolamide hydrochloride. The synthesis method is simple and easy to implement, high in chiral selectivity and low in cost, and the obtained dorzolamide hydrochloride is high in purity and suitable for industrial production.
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- PROCESS FOR THE PREPARATION OF DORAOLZMIDE HYDROCHLORIDE
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The present invention discloses an improved process for the preparation of dorzolamide hydrochloride the compound of Formula I.
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Page/Page column 13
(2018/04/21)
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- Process for Preparing Enantiomerically Enriched Oxamides
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The present invention relates to a chiral oxamide of formula (I) useful as an intermediate in the preparation of dorzolamide, and to the preparation thereof. The invention also relates to the preparation of dorzolamide, to the hydrochloride salt thereof, and to the active ingredient contained in a drug useful in the treatment of glaucoma, by means of the intermediate of formula (I).
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- PROCESS FOR PREPARING ENANTIOMERICALLY ENRICHED OXAMIDES
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The present invention relates to a chiral oxamide of formula (I) useful as an intermediate in the preparation of dorzolamide, and to the preparation thereof. The invention also relates to the preparation of dorzolamide, to the hydrochloride salt thereof, and to the active ingredient contained in a drug useful in the treatment of glaucoma, by means of the intermediate of formula (I).
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Page/Page column 15; 16
(2014/01/18)
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- PROCESS FOR PREPARING (4S, 6S)-4-(ETHYLAMINO)-5,6-DIHYDRO-6-METHYL-4H-THIENO-[2,3-B]THIOPYRAN-2-SULFONAMIDE-7,7-DIOXIDE AND ITS INTERMEDIATES
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Disclosed herein is an improved process for the preparation of (4S,6S)-4-(ethylamino)-5,6-dihydro-6-methyl-4H-thieno-[2,3-b]thiopyran-2-sulfonamide-7,7- dioxide (Dorzolamide) and its intermediates.
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Page/Page column 15
(2011/09/19)
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- PROCESS FOR PREPARING DORZOLAM IDE
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There is provided a process for preparing dorzolamide and processes for preparing intermediates useful in the preparation of dorzolamide. In particular, there is provided a process for preparing an acetoamido sulfone of formula (viii) comprising oxidation of a hydroxysulfonamide of formula (vii) in the presence of an oxidizing agent selected from the group consisting of: a peracid, tert-butyl hydroperoxide, dimethyl dioxirane, selenium dioxide, m-phenanthroline di-N-oxide, nitric acid and hydrogen peroxide. There is also provided a process for preparing an acetoamidosulfone of formula (ix-a) comprising converting a hydroxysulfone of formula (viii) to the acetoamidosulfone of formula (ix-a) in the presence of acetonitrile and an acid. There is also provided a process for separating the cis- and trans-isomers of dorzolamide from a mixture of the trans-isomer of dorzolamide and the cis-isomer of dorzolamide comprising reacting the mixture of isomers with a carboxylic acid.
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Page/Page column 21-22
(2009/01/20)
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- Method of making dorzolamide hydrochloride
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Processes for the preparation of dorzolamide hydrochloride and an intermediate of Formula IV, are provided.
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Page/Page column 9; 10
(2008/06/13)
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- PROCESS FOR PREPARING 5,6-DIHYDRO-4-(S)-(ETHYLAMINO)-6-(S) METHYL-4H-THIENO[2,3b]THIOPYRAN-2-SULPHONAMIDE-7,7-DIOXIDE HCI
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The present invention relates to an improved process for the preparation of 5,6-dihydro-4-(S)-(ethylamino)-6-(S)methyl-4H-thieno[2,3b]thiopyran-2-sulphonamide-7,7-dioxide hydrochloride of formula (I) commonly known as Dorzolamide Hydrochloride useful as an agent to reduce intraoccular pressure by inhibiting carbonic anhydrase enzyme.
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Page/Page column 14
(2008/06/13)
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- Process for preparing 5,6-dihydro-4-(S)-(ethylamino)-6-(S) methyl-4H-thieno[2,3b]thiopyran-2-sulphonamide-7,7-dioxide HCI
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The present invention relates to an improved process for the preparation of 5,6-dihydro-4-(S)-(ethylamino)-6-(S)methyl-4H-thieno[2,3b]thiopyran-2-sulphonamide-7,7-dioxide hydrochloride of formula (I) commonly known as Dorzolamide Hydrochloride useful as an agent to reduce intraoccular pressure by inhibiting carbonic anhydrase enzyme
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Page/Page column 10
(2008/06/13)
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- AN IMPROVED PROCESS FOR THE PREPARATION OF 5,6 -DIHYDRO -4H-4(S)-ETHYLAMINO-6(S)-METHYLTHIENO[2,3-b] THIOPYRAN-2-SULFONAMIDE- 7,7 -DIOXIDE AND ITS SALT
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The present invention relates to resolution of (cis, trans) 5,6 -dihydro -4H-4-ethylamino-6-methylthieno[2,3-b] thiopyran-2-sulfonamide-7,7 -dioxide using dibenzoyl -L- tartaric acid monohydrate or di-p-toluoyl-L-tarrtaric acid monohydrate as a chiral resolving agent in presence of methanol to obtain hemitartarate salt, purifying it to obtain hemitartarate salt of 5,6-dihydro-4 H-4 (S) -ethyl amino-6(S) methylthieno [2,3-b] thiopyran-2-sulfonamide - 7,7 -dioxide with de of >99% , Chemical purity >99.5% with cis isomer content of 0.1 % and further converting into its pharmaceutically acceptable salts, preferably hydrochloride salt.
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Page/Page column 7
(2008/06/13)
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- Novel crystalline form of dorzolamide hydrochloride
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The present invention relates to a novel crystalline form of dorzolamide hydrochloride, to processes for its preparation and a pharmaceutical composition containing it.
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Page/Page column 1; 2
(2008/06/13)
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- Process for obtaining 4-(N-alkylamino)-5,6-dihydro-4H-thien-(2,3-b)-thiopyran-2-sulfonamide-7,7-dioxides and intermediates
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The process for obtaining 4-(N-alkylamino)-5,6-dihydro-4H-thien-(2,3-b)-thiopyran-2-sulfonamide-7,7-dioxides (I) wherein R1 is H or C1-5 alkyl, and R2 is C1-5 alkyl, starts from the corresponding 4-(N-alkylamino)-5,6-dihydro-4H-thien-(2,3-b)-thiopyran-7,7-dioxides, and comprises protecting the alkylamine group, introducing a sulfonamide group and eliminating protecting group. Some compounds of formula (I) are inhibitors of the carbonic anhydrase and can be used in the treatment of elevated intraocular pressure.
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Page/Page column 12
(2008/06/13)
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