Process for the production of dinitrotoluene

US5689018A · 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: Nov 18, 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 from toluene and nitric acid in the presence of sulfuric acid in a two stage process in the first stage, toluene and nitric acid are reacted under isothermal conditions in amounts such that mononitrotoluene is produced. The reaction mixture is then separated into an organic phase and an acid phase. The organic phase is then further reacted with nitric acid under adiabatic conditions to produce dinitrotoluene. The reaction mixture is then separated into an organic phase and an acid phase. Dinitrotoluene is recovered from the organic phase. After at least 5% by weight water is removed from the acid phase and sufficient nitric acid to replace that consumed during the nitration reaction has been added, the acid phase may be recycled.