The Selective Oxidation Of Nitrotoluene

Nitrobenzaldehyde have very important application in the industry,which are the intermediates of explosives,medicine,pesticides,dyes and other chemicals.The synthesis methods of o-nitrobenzaldehyde and p-nitrobenzaldehyde were improved in this paper based on the industrial production ways.The synthesis conditions of o-nitrobenzaldehyde was improved in this paper.O-nitrobenzaldehyde was synthesized through catalytic bromination,hydrolysis and oxidation from o-nitrotoluene(ONT).The influence of bromination reaction,hydrolysis,oxidation conditions on the yield of o-nitrobenzaldehyde was studied in this paper.The results showed that optimized conditions were that n(HBr):n(H₂O₂:n(ONT)was 1.1:1.1:1,bromination time was 4h,hydrolysis reaction time was 12h,oxidation time was 2.5h.The temperature of bromination and hydrolysis reaction were 65-70℃,the oxidation temperature was 40-45℃.The synthesis conditions of p-nitrobenzaldehyde was improved in this paper.P-nitrobenzaldehyde was prepared through catalytic bromination,hydrolysis of p-nitrotoluene (PNT).The yield of p-nitrobenzaldehyde could reach 60.2 percent.The result showed that optimized conditions were that n(HBr):n(H₂O₂):n(PNT)was 2.2:2.2:1;bromination time was 3h,hydrolysis time was 30min,bromide temperature was 65-70℃,hydrolysis temperature was 90-100℃.A certain number of attempts were done in this paper on air oxidation method of p-nitrotoluene. The o-nitrobenzaldehyde and p-nitrobenzaldehyde were synthesized when o-nitrotoluene and p-nitrotoluene were selectively oxidized in the condition of organic amines as solvent,MnSO₄ as a catalyst in the atmosphere.