申请人:Bandodkar Hemant Ratanakar
公开号:US20120302795A1
公开(公告)日:2012-11-29
The present invention provides a method for the preparation of polymer grade 4,4′-dichlorodiphenyl sulfone in steps comprising reacting dimethyl sulfate and sulfur trioxide optionally containing a catalyst; reacting the formed dimethyl pyrosulfate with the unreacted sulfur trioxide optionally in the presence of a catalyst; reacting the reaction mixture with monochlorobenzene optionally containing a catalyst; optionally removing unreacted dimethyl sulfate; isolating crude 4,4′-dichlorodiphenyl sulfone using an organic solvent/organic solvent-water mixture; recovering the solvent from mother liquor; optionally recovering the isomeric mixture of dichlorodiphenyl sulfones from mother liquor; optionally, conversion of residual isomeric mixture of dichlorodiphenyl sulfones to a product selected from diphenyl sulfone, 2-aminodiphenyl sulfone; 2,4′-dihydroxydiphenyl sulfone, 4,4′-dihydroxydiphenyl sulfone; optionally recovering monochlorobenzene sulfonic acid and/or monochlorobenzene from the mother liquor; optionally recovering sulfuric acid from the residual liquor; optionally recycling the solvent; and purifying 4,4′-dichlorodiphenyl sulfone from crude followed by crystallization. Further the present invention discloses a process in which isomeric mixture of 4,4′-, 3,4′-, and 2,4′-dichlorodiphenyl sulfone produced during the preparation of 4,4′-dichlorodiphenyl sulfone is converted to value added products such as diphenyl sulfone, 2,4′-dihydroxydiphenyl sulfone, 4,4′-dihydroxydiphenyl sulfone and 2-aminodiphenyl sulfone.
本发明提供一种制备高分子级4,4'-二氯二苯砜的方法,包括以下步骤:反应二甲基硫酸酯和三氧化硫,可选地含有催化剂;将生成的二甲基焦硫酸酯与未反应的三氧化硫反应,可选地在存在催化剂的情况下;将反应混合物与单氯苯反应,可选地含有催化剂;可选地去除未反应的二甲基硫酸酯;使用有机溶剂/有机溶剂-水混合物分离粗4,4'-二氯二苯砜;从母液中回收溶剂;可选地从母液中回收二氯二苯砜异构体混合物;可选地将剩余的二氯二苯砜异构体混合物转化为选择自二苯砜、2-氨基二苯砜、2,4'-二羟基二苯砜、4,4'-二羟基二苯砜的产品;可选地从母液中回收单氯苯磺酸和/或单氯苯;可选地从残留液中回收硫酸;可选地回收溶剂;并通过结晶纯化粗4,4'-二氯二苯砜。此外,本发明还揭示了一种过程,其中在制备4,4'-二氯二苯砜的过程中产生的4,4'-、3,4'-和2,4'-二氯二苯砜异构体混合物转化为增值产品,例如二苯砜、2,4'-二羟基二苯砜、4,4'-二羟基二苯砜和2-氨基二苯砜。