Yield:114212-23-6 88.5%

Reaction Conditions:

with pyridinium 4-toluenesulfonate in 1,1,2,2-tetrachloroethane at 60; for 4 h;Inert atmosphere;

Steps:

1 Example 1. Preparation of compound 1-1

Under nitrogen atmosphere, dissolve 74.82g (0.4mol) of 2-bromo-4-methylphenol in 600mL of ultra-dry tetrachloroethane, then add 33.65g of dihydropyran (0.4mol) and 5.03g of p-toluenesulfonic acid Pyridine salt (0.02mol) was reacted at 60°C for 4h. Extracted with dichloromethane, washed with saturated brine, combined the organic phases and dried over anhydrous sodium sulfate. The filtrate was concentrated and purified by silica gel column chromatography (petroleum ether:ethyl acetate=200:1 (v/v)) to obtain 76.87 g of white solid with a yield of 88.5%.

References:

CN114315883,2022,A Location in patent:Paragraph 0126-0129