2,5-Bis(2-benzoxazolyl)thiophene

Synthesis of 2-chloromethylbenzo[ox]azole (feeding is mass fraction) Put 54.5 parts of o-aminophenol and 220 parts of chlorobenzene into the reactor, stir to form a suspension, and add 0.6 parts of catalyst pyridine. Under the protection of nitrogen and stirring, add 20.0 parts of 2-chloroacetyl chloride dropwise, heat to 80 ℃ after the addition is complete, gradually heat to 100 ℃ during the reaction, keep for 2 h, add 3 parts of o-toluene sulfonic acid, continue Under nitrogen protection, stir and reflux for 5 h. The chlorobenzene is distilled off to obtain the brown oily 2-chloromethylbenzo[ox]azole. Synthesis of bis(benzo[ox]azole-2-methyl)sulfide Put 63 parts of sodium sulfide into the reaction kettle, add 3 times water, and stir to dissolve. Subsequently, 0.8 part of benzyl n-tributylammonium bromide was added. Cool to 10 ℃. Add the α-chloromethylbenzo[oxox]azole produced in the previous step to dichloromethane to prepare a solution. Then add this solution dropwise to the sodium sulfide solution, react for 3 hours, let it stand, discard the water layer, wash the organic layer until it is neutral, stir and mix with the dried sodium sulfate and the washed organic matter, dehydrate, and filter Out of Yuan Mingfen. The filtrate was evaporated in vacuo to dichloromethane. Cool to crystallize, and recrystallize with methanol. Obtain pure bis(benzo[ox]azole-2-methyl)sulfide. The formation of brightener EBP First prepare sodium methoxide solution with sodium metal and anhydrous methanol, cool this solution to 0 ℃, add glyoxal and stir for 4 h, and gradually produce crystal precipitation. That is, 2, 5-dibenzo[ox]azolylthiophene is neutralized with dilute acid, filtered, the filter cake is washed with water to neutrality, and then vacuum dried to obtain the crude brightener EBF. Then it was recrystallized from chlorobenzene to obtain a refined product.

Mainly used for commercial whitening agent EB, but also for whitening and brightening of various polyolefin plastics, BS engineering plastics, organic glass, etc.

Molecular Weight:318.4
XLogP3:4.7
Hydrogen Bond Acceptor Count:5
Rotatable Bond Count:2
Exact Mass:318.04629874
Monoisotopic Mass:318.04629874
Topological Polar Surface Area:80.3
Heavy Atom Count:23
Complexity:399
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes