Patent · US Expired

Process for the production of dinitrotoluene

US4663490A · kind A · utility

10Cited by

7References

13Claims

0Family size

Assignee

BAYER HEALTHCARE LLC · DE

Inventors

Rudolf Gerken · Krefeld, DE
Gunter Lailach · Krefeld, DE
Dieter Becher · Brunsbüttel, DE
Harro Witt · Kuden, DE

Key dates

Filing date	Mar 12, 1985
Grant date	May 5, 1987
Priority date	—
Expiry date	Mar 12, 2005

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC07C201/08
WIPO fieldOrganic fine chemistry
WIPO sectorChemistry

Abstract

In the production of dinitrotoluene by a two-stage reaction of toluene with nitric acid in the presence of sulphuric acid, wherein toluene is nitrated to mononitrotoluene in the first stage using spent acid from the second stage, and the mononitrotoluene is nitrated to dinitrotoluene in the second stage using concentrated spent acid from the first stage, the improvement which comprises concentrating spent acid under vacuum in an indirectly-heated evaporator and feeding mononitrotoluene into the superheated vapor of the evaporator.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.