- 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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- Synthetic process of dorzolamide Hydrochloride intermediate
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The invention discloses a synthetic process of a dorzolamide Hydrochloride intermediate. According to the invention, mild zinc borohydride is adopted as a reducing agent; raw material compounds IIa 4-acetamido-5, 6-dihydro-6-methyl-4H-thieno [2, 3-b] thiopyran-2-sulfonamide-7, 7-dioxide and IIb ((4S, 6S)-4-acetamido-5, 6-dihydro-6-methyl-4H-thieno [2, 3-b] thiopyran-2-sulfonamide-7, 7-dioxide) arereduced at the temperature of 60-120 DEG C, acetamido is reduced into ethylamino, usage of a reducing agent which is highly toxic and high in operation danger coefficient is avoided, the whole reaction is easier to control, and the whole reaction process is milder and more environmentally friendly.
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Paragraph 0036; 0053; 0076-0083
(2020/06/20)
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- PHOSPHATE-FREE PHARMACEUTICAL COMPOSITION FOR THE TREATMENT OF GLAUCOMA
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The invention relates to a phosphate-free pharmaceutical composition which comprises at least one FP prostanoid receptor agonist and/or at least one prostamide receptor agonist and also citrate salts and/or citric acid.
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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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- 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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(2008/06/13)
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