反应详情

温度

-10 °C

A solution of 2.60 g of 4-(2,2-dibromovinyl)-4'-pentylbiphenyl in 50 ml of absolute tetrahydrofuran was placed at -78° C. in a sulphonation flask under argon gasification and treated within 5 minutes with 14.5 ml of a 1.2N solution of butyl lithium in hexane. After completion of the addition, the mixture was warmed to -10° C. within 10 minutes and then, after renewed cooling to -78° C., treated with a solution of 1.5 ml of phenyl cyanate in 10 ml of absolute tetrahydrofuran. The mixture was subsequently stirred at -78° C. for a further 30 minutes, then poured into 100 ml of water and extracted three times with 100 ml of diethyl ether each time. The organic phases were washed twice with 50 ml of water each time, dried over magnesium sulphate and concentrated. Low-pressure chromatography (0.5 bar) of the residue (2.51 g) on silica gel with hexane followed by 2% ethyl acetate/petroleum ether and subsequent recrystallization from methanol gave 1.02 g (58%) of (4'-pentyl-4-biphenylyl)propiolonitrile as colourless crystals (purity 99.6%); m.p. (C-N) 51.0° C., cl.p. (N-I) 120.2° C.

1. additionAfter completion of the addition
2. temperatureafter renewed cooling to -78° C.
3. extractionextracted three times with 100 ml of diethyl ether each time
4. washThe organic phases were washed twice with 50 ml of water each time
5. dry with materialdried over magnesium sulphate
6. concentrationconcentrated
7. customLow-pressure chromatography (0.5 bar) of the residue (2.51 g) on silica gel with hexane followed by 2% ethyl acetate/petroleum ether and subsequent recrystallization from methanol