Method for producing o-methyl hydroquinone from o-methyl p-benzoquinone through reduction of sulfur series reducing agent

Abstract

The invention discloses a method for producing o-methyl hydroquinone from o-methyl p-benzoquinone through reduction of a sulfur series reducing agent. The method comprises the following steps: addingwater in an o-methyl-p-benzoquinone extracting solution, introducing in the sulfur series reducing agent, stirring for reacting, and sampling and analyzing until no o-methyl-p-benzoquinone exists in asystem, i.e., reaching a reaction endpoint; standing the solution, and extracting, thus obtaining an o-methyl hydroquinone extracting solution; extracting a mixed solution generated through reductionreaction, thus obtaining an extracting solution; adding water in the extracting solution, and removing an extracting agent by carrying out decompression and desolventization, thus obtaining an o-methyl hydroquinone water solution; then carrying out decoloration, vacuum concentration, cooling and crystallizing, and drying, thus obtaining an o-methyl hydroquinone product. Compared with a traditional iron powder reduction technology, the method disclosed by the invention is moderate in reaction conditions, is efficient and energy-saving, is clean and environmentally friendly and has high conversion rate and good product quality; meanwhile, compared with palladium carbon catalytic hydrogenation, the method is short in reaction time, low in input cost and small in product loss, a reaction product-sulfuric acid can be used as a raw material for preparing o-methyl p-benzoquinone through an aniline method, and the method is more economic.

Description

technical field [0001] The invention discloses a method for producing o-methylhydroquinone by reducing o-methyl-p-benzoquinone with a sulfur series reducing agent, belonging to the field of fine chemicals. technical background [0002] o-methyl-p-benzoquinone and o-methyl-p-benzoquinone are important intermediates in organic synthesis. For o-methyl-p-benzoquinone after oxidation of o-methyl-p-benzoquinone, o-methyl-p-benzoquinone is added by iron powder or catalyst The traditional method of hydrogen reduction to generate o-methylhydroquinone, especially the iron powder reduction process, has the following obvious deficiencies: [0003] 1. The iron sludge produced has great environmental pollution; [0004] 2. High reaction temperature (90-100°C), o-methyl-p-benzoquinone is easy to polymerize and deteriorate, increasing material loss and reducing product yield. [0005] 3. The equipment has high requirements and wears a lot. [0006] 4. Poor product quality, especially hig...

AI Technical Summary

Problems solved by technology

[0003] 1. The iron sludge produced has great environmental pollution;

[0004] 2. High reaction temperature (90-100°C), o-methyl-p-benzoquinone is easy to polymerize and deteriorate, increasing material loss and reducing product yield

[0005] 3. High equipment requirements and large wear and tear

[0006] 4. The product quality is poor, especially the content of ash and heavy metals is high, it is difficult to produce high-quality o-methylhydroquinone products

[0008] 1. The cost of palladium carbon catalyst is high, the catalyst is easy to be poisoned during use, and it is difficult to restore the activity. The yield of the whole reaction product is reduced and the loss of catalyst is large if the whole reaction is continued to be used;

[0009] 2. Long reaction time and low production efficiency;

[0010] 3. The production operation is complicated and the safety hazard is great;

[0011] 4. After the reaction, if the product is not added with antioxidant in time, it is easy to oxidize, and the product loss is large