Process for the production of dinitrotoluene

US5679873A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Uwe Klingler · Dormagen, DE
• Thomas Schieb · Rösrath, DE
• Gerhard Wiechers · Leverkusen, DE
• Jurgen Zimmermann · Salzgitter, DE

Key dates

• Filing date: Aug 3, 1995
• Grant date: Oct 21, 1997
• Expiry date: Aug 3, 2015

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C201/08
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Dinitrotoluene is produced in a two-stage process from toluene and nitric acid in the presence of sulfuric acid under adiabatic conditions in the presence of nitrating acids made up of specified components. The reaction product of the first phase is separated into an acid phase and an organic phase containing the mononitrotoluene. Some water is removed from the acid phase, nitric acid is added and the resultant mixture is recycled. The organic phase containing mononitrotoluene is further nitrated to produce the dinitrotoluene. This nitration mixture is also separated into an acid phase and an organic phase. The acid phase is treated to remove some water, nitric acid is added and the resultant acid mixture is recycled. Dinitrotoluene is recovered from the organic phase. This process is advantageous in that dilute nitric acid may be used and the heat of the nitration reaction is utilized.