公开(公告)号：DE59204414D1

公开(公告)日：1996-01-04

申请号：DE59204414

申请日：1992-08-19

Applicant: HOECHST AG

Inventor： RITTER EBERHARD DR ,  SCHAEFER HANS ,  VOLLHEIM THOMAS DR ,  SCHOTTLER MARTIN DR

IPC: C07C227/08 ,  C07C227/16 ,  C07C227/18 ,  C07C229/58 ,  C07C229/62

Abstract: The invention relates to a process for the preparation of dialkyl 2,5-di-(phenylamino)terephthalates of the formula (I) in which R denotes a hydrogen atom or a methyl group and R% denotes a methyl or ethyl group, by dehydrogenation (oxidation) of the corresponding dialkyl 2,5-di-(phenylamino)dihydro(3,6)terephthalate with oxygen, characterised in that a solution or suspension of the dialkyl 2,5-di-(phenylamino)dihydro(3,6)terephthalate in aromatic hydrocarbons is blanketed with oxygen in a stirring vessel, this reaction mixture is circulated through a spray device, so that the sprayed reaction mixture is dispersed above the reaction mixture present in the stirring vessel, the sprayed reaction mixture being mixed with the circulating gas. The process has the advantage of a short reaction time, combined with favourable space-time yields and simplicity in terms of apparatus.

公开(公告)号：BR9203289A

公开(公告)日：1993-04-06

申请号：BR9203289

申请日：1992-08-21

Applicant: HOECHST AG

Inventor： RITTER ERHARD DR ,  SCHAEFER HANS ,  VOLLHEIM THOMAS DR ,  SCHOTTELER MARTIN DR

IPC: C07C227/08 ,  C07C227/16 ,  C07C227/18 ,  C07C229/58 ,  C07C229/62 ,  C07C219/34

Abstract: The invention relates to a process for the preparation of dialkyl 2,5-di-(phenylamino)terephthalates of the formula (I) in which R denotes a hydrogen atom or a methyl group and R% denotes a methyl or ethyl group, by dehydrogenation (oxidation) of the corresponding dialkyl 2,5-di-(phenylamino)dihydro(3,6)terephthalate with oxygen, characterised in that a solution or suspension of the dialkyl 2,5-di-(phenylamino)dihydro(3,6)terephthalate in aromatic hydrocarbons is blanketed with oxygen in a stirring vessel, this reaction mixture is circulated through a spray device, so that the sprayed reaction mixture is dispersed above the reaction mixture present in the stirring vessel, the sprayed reaction mixture being mixed with the circulating gas. The process has the advantage of a short reaction time, combined with favourable space-time yields and simplicity in terms of apparatus.

公开(公告)号：ES2081533T3

公开(公告)日：1996-03-16

申请号：ES92114144

申请日：1992-08-19

Applicant: HOECHST AG

Inventor： RITTER EBERHARD DR ,  SCHAFER HANS ,  VOLLHEIM THOMAS DR ,  SCHOTTLER MARTIN DR

IPC: C07C227/08 ,  C07C227/16 ,  C07C227/18 ,  C07C229/58 ,  C07C229/62

Abstract: The invention relates to a process for the preparation of dialkyl 2,5-di-(phenylamino)terephthalates of the formula (I) in which R denotes a hydrogen atom or a methyl group and R% denotes a methyl or ethyl group, by dehydrogenation (oxidation) of the corresponding dialkyl 2,5-di-(phenylamino)dihydro(3,6)terephthalate with oxygen, characterised in that a solution or suspension of the dialkyl 2,5-di-(phenylamino)dihydro(3,6)terephthalate in aromatic hydrocarbons is blanketed with oxygen in a stirring vessel, this reaction mixture is circulated through a spray device, so that the sprayed reaction mixture is dispersed above the reaction mixture present in the stirring vessel, the sprayed reaction mixture being mixed with the circulating gas. The process has the advantage of a short reaction time, combined with favourable space-time yields and simplicity in terms of apparatus.