Provided are compounds of Formula I:
and pharmaceutically acceptable salts and esters thereof. The compounds, compositions, and methods provided are useful for the treatment of virus infections, particularly hepatitis C infections.
Novel polyvinyl alcohol and process for producing polyvinyl alcohol by hydrolysis catalysed by acids
申请人:Kuraray Co., Ltd.
公开号:EP0328102A2
公开(公告)日:1989-08-16
The polyvinyl alcohol of the present invention is a partially saponified polyvinyl alcohol having a saponification degree of 70 to 98 mol% and containing a larger amount of methanol-soluble substances than that contained in polyvinyl alcohols having the same saponification degree obtained by known processes, and is novel.
The process for producing polyvinyl alcohol of the present invention comprises saponifying polyvinyl esters in a solvent of a polyoxyalkylene ether having in the molecule thereof a structural unit represented by the general formula [I]:
wherein R' and R2 each represents an alkylene group having 2 to 5 carbon atoms in the main chain thereof, which may be substituted with a lower alkyl group or lower alkoxy group; t is an integer of 0 or 1; m and n each represents 0 or an integer of 1 to 10; and I + m + n > 2;
with the catalyst of an organic (aliphatic or aromatic) sulfonic acid at an elevated temperature in the presence of water. The process can produce polyvinyl alcohol having a higher saponification degree at a higher reaction rate than conventional hydrolysis processes catalysed by acids.
本发明的聚乙烯醇是一种部分皂化的聚乙烯醇,其皂化度为 70 至 98 摩尔%,与通过已知工艺获得的具有相同皂化度的聚乙烯醇相比,含有更多的甲醇可溶物,具有新颖性。
本发明生产聚乙烯醇的工艺包括在聚氧亚烷基醚的溶剂中对聚乙烯醇酯进行皂化,聚氧亚烷基醚的分子中含有通式[I]所代表的结构单元:
其中 R' 和 R2 分别代表在其主链上具有 2 至 5 个碳原子的亚烷基,该亚烷基可被低级烷基或低级烷氧基取代;t 为 0 或 1 的整数;m 和 n 分别代表 0 或 1 至 10 的整数;且 I + m + n > 2;
有机(脂肪族或芳香族)磺酸催化剂,在有水存在的高温下进行。与传统的以酸为催化剂的水解工艺相比,该工艺能以更高的反应速率生产出皂化度更高的聚乙烯醇。