A study on the ammoxidation reactions halotoluene compounds.

number: 
135
English
department: 
Degree: 
Imprint: 
Chemistry
Author: 
Ali Omer Al-Chalabi
Supervisor: 
Dr. Muthana Shanshal
year: 
1995

Abstract:

Ammoxidation reaction is a new catalytic method of preparing organic nitriles from the corrsponding alkyl-subsituted aromatic, aliphatic, alicyclic and heterocyclic compounds with ammonia and oxygen in the gaseous phase at the elevated temperature and in the presence of catalyst, as in the following equation ;
Cat. R(CH3)n+nNH3+1.5nO2 ------------------------------------------------>R(CN)n + 3nH2O 300°C - 500°C R= alkyl.phenyl or heteroaromatic ring. n=1,2,3 The catalyst employed in the ammoxidation reaction is comprising freshly prepared activated alumina-supported V2O5 and SnO2. It shows improved activity .selectivity and mechanical stability. The purpose of the present research is :In this research , the factors influenced the ammoxidation reaction of halotoluenes were studied , and the percentage of the yield and conversion calculated. 1. In the ammoxidation reaction of ochlorotolouene , the influence of the different ratios of oxygen and ammonia were studied indetail. It was found that the oxygen amount is preferable to be 70% of the stochiometric amount and the ammoina mole ratio of reactants was (1:5:1.05) of
(o-chlorotlouene:ammonia: oxygen) . the highest calculated yield and percentage at these conditions were 62% and 37% respectively. 2- For the p-chlorotlouene ammoxidation reaction, different ratios of oxygen applied at the same mole ratio of ammonia of 5:1. it was found that amount is preferable to be 70% of the stochiometric amount, the calculated yield and conversion percentage at these conditions and 60%
respectively. mote ratio was found from the ammoxidation reaction of o- chlorotoluene and pchlorotoluene was (1:5:1.05) of (halotolouene:NH3:O2). This optimum condition were applied for the other halotolouenes which are ,m- chlorotolouene. 4- From this study, it was found that:- a- For the chlorotoluene the conversion percentage increased in the order of p->m->o-. The yield percentage increased in the order of p->o->m-. b- For the bromotolouene the conversion percentage increased in the order p->m->o-. The yield percentage increased in the order o->p->m->. c- The conversion of m- and pbromotolouene are greater than that of corresponding m- and p-chlorotoluene. The conversion of o-chlorotoluene is greater than that of o-bromotoluene.