- Para-ester synthesis process for recycling hydrogen chloride
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The invention discloses a para-ester synthesis process capable of recycling hydrogen chloride, which is characterized by comprising the following steps: (1) preparing chlorosulfonic acid; absorbing the hydrogen chloride gas generated in the chlorosulfonation link through an original HCl absorption tower, and resolving to generate pure hydrogen chloride gas; reacting the hydrogen chloride gas withpure sulfur trioxide gas in a primary reaction tower to obtain gaseous chlorosulfonic acid; condensing the gaseous chlorosulfonic acid and entering in a secondary reaction tower, and fully reacting aside reaction product in the primary reaction tower with excessive sulfur trioxide and hydrogen chloride to further generate chlorosulfonic acid; (2) preparing para-ester; preparing chlorosulfonated substances in a sulfonation reaction kettle; diluting and carrying out suction filtration, and then carrying out a reduction reaction, a condensation reaction and an esterification reaction to preparethe para-ester. The hydrogen chloride generated in the chlorosulfonation link is recovered and reacts with sulfur trioxide gas to prepare chlorosulfonic acid, the chlorosulfonic acid serves as a raw material in the chlorosulfonation link, the para-ester is further prepared, and cyclic utilization is achieved.
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Paragraph 0086-0091; 0106-0111; 0126-0131; 0146-0151
(2020/05/01)
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- Metalloprotease inhibitors
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A compound selected from those of the formula (I): wherein: R1represents hydrogen or halogen, or alkyl or alkoxy, R2represents hydroxy, alkoxy or —NHOH, Ar1represents phenylene or biphenylene, X represents oxygen or sulphur, NR, —C≡C— or a bond, R represents hydrogen or alkyl, n is an integer from 0 to 6 inclusive, Ar2represents any one of the groups as defined in the description, its isomers and addition salts thereof with a pharmaceutically-acceptable acid or base, and medicinal products containing the same which are useful as metalloprotease inhibitors.
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Page column 9
(2008/06/13)
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