A kind of method that takes meta-position oil as raw material to prepare m-phenylenediamine

Abstract

The invention discloses a method for preparing m-phenylenediamine using nitrochlorobenzene meta-oil as raw material, which comprises the following steps: (1) Nitrification of nitrochlorobenzene meta-oil: adding nitrochlorobenzene meta-oil Concentrated sulfuric acid, heat up, add fuming nitric acid dropwise, react, stand still to separate the waste acid, and obtain a mixture of 2,4-nitrochlorobenzene and 3,5-dinitrochlorobenzene; (2) Catalytic hydrogenation reaction: The mixture of 2,4-dinitrochlorobenzene and 3,5-dinitrochlorobenzene is used as a raw material, methanol is used as a solvent, an alkaline substance is used as an acid-binding agent, and a precious metal palladium-carbon is used as a catalyst, and hydrogen gas is introduced. Get m-phenylenediamine. The present invention finds a new method for treating meta-oil of nitrochlorobenzene, which turns waste into treasure; compared with other methods for treating meta-oil, this method is simple and direct, and conforms to atomic economic benefits; it will not produce other unnecessary Necessary side reactions, the process is simple and easy to operate; compared with the reduction of m-dinitrobenzene to prepare m-phenylenediamine, it is more environmentally friendly and has a lower cost.

Description

technical field [0001] The invention belongs to the field of catalytic hydrogenation in chemical production, and in particular relates to a method for preparing m-phenylenediamine using meta-oil as a raw material. Background technique [0002] M-phenylenediamine, also known as 1,3-diaminobenzene, is a white needle-like crystal. It is an important organic chemical raw material and intermediate, and is widely used in industries such as dyes, washing chemicals, rubber, and national defense. Due to the strong coupling ability of m-phenylenediamine, azo dyes, fur dyes, reactive dyes and sulfur dyes can be produced in the dye industry, and it is also used to produce hair dyes, petroleum additives, rubber antioxidants, etc. It is widely used in various fields. [0003] The traditional method of producing m-phenylenediamine: use m-dinitrobenzene as raw material to prepare m-phenylenediamine by iron powder reduction or alkali sulfide reduction process. These two reduction processes ...

AI Technical Summary

Problems solved by technology

But the problem that this patent exists is: sodium methylate solution is in etherification reactor, in order to make p-nitrochlorobenzene fully etherified, usually need to add excess sodium methylate solution, and this just exists excessive sodium methylate to be in p-nitrochlorobenzene At the same time as benzene reacts, it will also react with m-nitrochlorobenzene to produce heavy component impurities, so that m-nitrochlorobenzene cannot be fully and completely extracted, affecting the yield of m-nitrochlorobenzene and causing a waste of resources