4.
    发明专利
    未知

    公开(公告)号:BR7705098A

    公开(公告)日:1978-04-04

    申请号:BR7705098

    申请日:1977-08-03

    Applicant: HOECHST AG

    Abstract: Improved process for the sulfatation of the hydroxy group of a beta -hydroxy-ethylsulfonyl group present in compounds selected from the dyestuff class which comprises carrying out the reaction in a machine operating with a kneading action and effect and with the use of only 1 to 5 times the equimolar amount of a concentrated sulfuric acid, of oleum or sulfur dioxide itself. The beta -sulfatoethylsulfonyl group containing dyestuffs, thus prepared have a high purity and are obtained in a high yield and esterification rate. Above all, the novel process is distinguished by a highly reduced salt and acid content of the waste water.

Patent Agency Ranking