ChemicalBook CAS DataBase List Bispyrithione

Bispyrithione synthesis

4synthesis methods

Product Name:Bispyrithione
CAS Number:3696-28-4
Molecular formula:C10H8N2O2S2
Molecular Weight:252.31

1, drop into successively the 600g2-chloropyridine in the 5000ml four-hole boiling flask, 100g maleic and acid anhydrides, 600g hydrogen peroxide (35%) are opened to stir and are warmed up to 60 ℃ of successive reactions 12 hours, make 2-chloropyridine-N-oxide water solution.
2, the 2-chloropyridine that uses the 4000g2-methyl chloride to divide four extractions to make-N-oxide water solution merges extraction phase, and condensing crystal makes sterling 2-chloropyridine-N-oxide compound.
3, the 2-chloropyridine that purification is obtained-N-oxide compound, 430g sodium sulphite, the 2000g high purity water, drop into successively in the 5000ml four-hole boiling flask, open and stir, be warming up to 70 ℃, along with the carrying out of reaction added a part of yellow soda ash in good time, the PH of adjustment system is stabilized in 9～10, and reaction finishes 70 ℃ of insulations 2 hours, and insulation finishes to cool.Make the pyrithione sodium water solution.
4, use an amount of dilute sulphuric acid to adjust the PH to 2 of pyrithione sodium water solution system, separate out a large amount of white crystals.Filtrated stock cleans solid, namely gets pyrithione.
5, the pyrithione that the reaction of upper step is obtained, the 1000g ultrapure water drops in the plastic cup, the unlatching dispersed with stirring is even, then slowly splash into 220g hydrogen peroxide (35%), reaction is 1 hour about 50 ℃, make finished product Bispyrithione 497g (99.72%, five step of content overall yield of reaction: 74.6%).

1121-31-9 Synthesis

1121-31-9
177 suppliers
$16.00/5g

3696-28-4
126 suppliers
$19.80/5mg

Yield:3696-28-4 92.3%

Reaction Conditions:

with hypochloric acid;p-dodecylbenzenesulfonic acid sodium salt;urea in lithium hydroxide monohydrate at 45 - 60; for 1 h;Reagent/catalyst;

Steps:

1.III; 2-4; 1-8 Step III: Bispyridinethione Synthesis

(1) oxidant in the present embodiment is hypochlorous acid-urea solution, and the mol ratio of hypochlorous acid and urea is 1.2:1.0, and its preparation process is as follows: take 300g 13% sodium hypochlorite solution, feed carbon dioxide gas to saturation, spare.26.5 g of 99% urea was added to the above solution and stirred evenly to obtain a hypochlorous acid-urea solution. (2) take by weighing 100g 2-mercaptopyridine-N-oxide and 300g pure water in 1000ml four-necked flask and make it dispersed, add sodium dodecylbenzenesulfonate 1.4g, stir and dissolve, be warming up to 45 ,Add the prepared hypochlorous acid-urea solution dropwise; after the dropwise addition,The temperature was raised to 55-60°C for 1 hour, suction filtration, washing, ethanol purification,Dry under reduced pressure at 55° C. to obtain 90.8 g of off-white solid bispyridinethione with a content of 99.0% and a yield of 92.3%.

References:

CN113999171,2022,A Location in patent:Paragraph 0029; 0033-0064

3811-73-2 Synthesis