Synthesis method for high-quality and low-cost bispyrithione

Abstract

The invention discloses a synthesis method for synthesizing high-quality and low-cost bispyrithione and relates to a synthesis method for the bispyrithione. The synthesis method comprises the following steps of: 1, performing mild oxidation reaction on halogenated pyridine and hydrogen peroxide in the presence of a catalyst to synthesize halogenated pyridine-N-oxide; 2, extracting and purifying the halogenated pyridine-N-oxide by using a solvent; 3, reacting the purified halogenated pyridine-N-oxide and a sulfhydrylation reagent under the alkaline condition to obtain 2-mercaptopyridine-N-oxide sodium; reacting 4,2-mercaptopyridine-N-oxide sodium under the acid condition to obtain 2-mercaptopyridine-N-oxide; and reacting 5,2-mercaptopyridine-N-oxide and oxidant to obtain a targeted product bispyrithione. By the method, the quality stability of a product can reach more than 99.5 percent; reaction conditions are mild; and cost is low.

Description

Technical field:

[0001] The invention relates to a method for synthesizing bispyridinethione, in particular to a method for synthesizing bispyridinethione with high quality and low metal ion sensitivity. Background technique:

[0002] Bipyridinethione (BPT) is an excellent anti-dandruff and antipruritic agent with broad-spectrum antibacterial properties. It is widely used in transparent plastics, pharmaceutical intermediates and other fields. It has a certain solubility in water and can be used in transparent shampoo systems Medium, without affecting the pearlescent effect of the shampoo system. Due to its unique molecular structure (the structural formula is as follows:) compared with the traditional anti-dandruff agent zinc pyrithione (ZPT), it greatly reduces its sensitivity to metal ions and exists more stably in the shampoo system.

[0003] At present, there are no domestic and foreign reports on the route of synthesizing bispyridinethione from halogenated pyridines. T...