Diethylene Glycol Monobutyl Ether → 3-Oxo-2-(4-tert-butylphenyl)-3-(1,3,4-trimethylpyrazol-5-yl)propionitrile

Participants

Reaction Conditions

Reaction Steps

In a 2000 ml-reaction flask equipped with a rectification column and a separating tank, 83.7 g (483 mmol) of 4-tert-butylphenylacetonitrile, 80.0 g (439 mmol) of 1,3,4-trimethylpyrazol-5-carboxylic acid ethyl ester, 640 g of heptane, and 160 g of diethylene glycol monobutyl ether were added, the atmosphere was substituted with nitrogen, then azeotropic dehydration was carried out by heating at 90 to 95° C. for 1 hour. The temperature was maintained, 93.2 g (482 mmol) of 28% sodium methoxide methanol solution was added dropwise over 3 hours, and the resulting mixture was further reacted for 10 hours. After cooling to 30° C. or less, 600 g of water was added to separate out heptane phase, and the resulting aqueous phase was washed with 160 g of heptane and 400 g of toluene was added, then pH was adjusted to 7 with 35% hydrochloric acid. After separating into phases, the toluene phase was washed two times with 160 g of water to obtain a toluene solution containing 116 g (yield 85.1%) of 3-oxo-2-(4-tert-butylphenyl)-3-(1,3,4-trimethylpyrazol-5-yl) propionitrile. Toluene was distilled off under a reduced pressure, then 120 g of di-n-butyl ether was added and completely dissolved therein at a temperature of 120° C. Thereafter, the solution was cooled to 20° C., the resulting crystal was further dispersed in 150 g of di-n-butylether, 200 g of n-hexane was added therein and stirred at 10° C. for 1 hour. The resulting crystal was filtered and washed with 150 g of n-hexane to obtain 92.3 g of 3-oxo-2-(4-tert-butyl phenyl)-3-(1,3,4-trimethylpyrazol-5-yl) propionitrile (melting point 178° C.).

Provenance & Evidence