Synthesis
1Synthesis process of propyl phthalide chloride
250kg of propionic acid and 185kg of phosphorus trichloride were put into 500L glass-lined reaction pot, slowly heating reaction, stirring and holding at 50 for 6h, static for 3h, divided into the lower layer of phosphine, that is, 297kg of propionic phthalic acid chlorine, yield 95%, the obtained propionic phthalic acid chlorine does not need to be purified, can be used for the next step in the production.
(2) 225kg of anhydrous aluminum trichloride and 160kg of toluene into 500L glass-lined reaction pot, jacket cooling, under stirring slowly add 120kg of propyl phthalide chloride drops, to maintain the internal temperature does not exceed 30 , add the end of the stirring at room temperature lh, and then slowly warmed to 82 , holding 2h after cooling, the reaction liquid droplets held in the It ice water mixed with the 2000L glass-lined reaction pot of low-temperature hydrolysis, stationary Delamination, take the upper layer of oily material, water and saturated soda solution washed to neutral, drying, atmospheric pressure off the toluene, and then collect 96-100 / 930Pa fractions, the content of more than 98% 4-methylpropiophenone, yield 88%.
