Synthesis method of DPA

Abstract

The invention discloses a synthesis method of DPA. The method comprises the following steps: (1) adding methanol, o-nitrotoluene, a catalyst, concentrated sulfuric acid, distilled water into an autoclave, performing heating with stirring to 50 DEG C, evacuating air and then introducing hydrogen, controlling a pressure in the autoclave to 0.1 MPa, carrying out a reaction for 5 h, then performing suction filtration, distilling a filtrate to remove methanol, diluting a residual solution by adding water and then adjusting pH to be neutral with ammonia water, performing extracting with toluene, washing an organic phase with a dilute sodium hydroxide solution, and performing reduced pressure distillation on the organic phase to obtain 4-methoxy-2-methylaniline; and (2) adding 4-methoxy-2-methylaniline, phenol naphthalene, cyclohexanone, and the catalyst into an autoclave, replacing air with nitrogen, performing heating to 250 DEG C, controlling a pressure in the autoclave to 1 Mpa, performing cooling to room temperature after a reaction is completed, filtering a reaction solution, and performing reduced pressure distillation on a filtrate and collecting various fractions, wherein a latter fraction is DPA. The raw materials are cheap and easy to obtain, the operation is simple, the yield is high, the energy consumption is low, and the method has practical value and economic value, andis suitable for enterprise production.

Description

technical field [0001] The invention belongs to the technical field of compound synthesis, in particular to a synthesis method of DPA. Background technique [0002] With the continuous development of the dye industry, the use of dyes has developed from the dyeing of fibers and fabrics to high-tech information recording, energy conversion, medical diagnosis, microelectronics industry, and biological industry. Due to the rapid development of intelligence and information industry and the wide application of computers and fax machines, the demand for pressure-sensitive and heat-sensitive dyes is growing rapidly. In my country, fluorane pressure-sensitive and heat-sensitive dyes are being developed. With the rapid development of my country's economy, the demand for such products is increasing day by day, and the market potential is huge. The successful development of such dyes will bring economic benefits that cannot be underestimated. benefit. [0003] 2-Methyl-4-methoxydipheny...

AI Technical Summary

Problems solved by technology

At present, the production of DPA in China has not been industrialized, and some synthesis methods in the pilot test have disadvantages such as unavailable raw materials, long reaction time, complicated operation, high energy consumption, high temperature, high pressure, and low yield, which are not conducive to industrialization and lack of market. Competitiveness