Highly Regioselective Process for the Production of Important Industrial Intermediates in High Yields

Journal Article

Alotaibi, Mohammad H. . 2013

• Publication Work Type: Research
• Magazine \ Newspaper: Journal of Petroleum & Environmental Biotechnology
• Issue Number: 6
• Volume Number: 4
• Pages: 117

Publication Abstract

We have investigated the dinitration of toluene over zeolite under various reaction conditions with the aim to produce 2,4-DNT selectively and in high yield. The best result obtained under produce 2,4-DNT in 90%. Therefore, in an attempt to push the reaction to completion, various acid anhydrides (e.g. anhydrides with different carbon chain length, halogenated acetic anhydrides) were used along with various quantities of zeolites and reagents. It was found that chloroacetic anhydride over Hβ produced 2,4-dinitrotoluene in 98% yield in which 2,4-:2,6-DNT was 49:1. Also, propionic anhydride under similar reaction conditions produced 2,4-DNT in 98% but in excellent selectivity (2,4-:2,6-DNT=123:1). This result is simply the highest for direct dinitration of toluene ever recorded. In contrast to traditional method, the system containing propionic anhydride, nitric acid, zeolite Hβ gave excellent yield of 2,4-dinitroyoluene with excellent selectivity and the only by-product produced during the process was the propionic acid which can be recycled easily. Also, the zeolite can easily remove from the reaction mixture by simple filtration, activated and reused to give good results for several times. The system was applied successfully to various mono-substituted benzenes (e.g. alkyl and akyloxybenzene).