diethyl 2-cyanobutanedioate

Conditions: temp:2.51; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Water (120 mL) and 15 mL of 35% hydrochloric acid were added to 5.6 g (0.06 mol) of aniline, and the mixture was dissolved. Subsequently, 24 mL of water having dissolved therein 4.2 g (0.06 mol) of sodium nitrite was added dropwise thereto with stirring under ice cooling to 0 to 5° C., and the resulting solution was stirred for 1 hour to prepare benzenediazonium chloride. An aqueous solution of this diazonium salt was added dropwise to a 120 mL pyridine solution containing 10.2 g (0.06 mol) of diethyl α-cyanosuccinate with stirring under ice cooling. After the dropwise addition, the solution was stirred under ice cooling for 1 hour and then at room temperature for 1 hour. When the reaction was completed, 240 mL of an aqueous 2% sodium hydroxide solution was added, followed by stirring for 2 hours. The obtained reaction solution was added dropwise to 240 mL of 35% hydrochloric acid under ice cooling, and the precipitated crystal was collected by filtration, washed with 10 mL of water and dried by a hot air drier to obtain 8.4 g of the crude crystal of the title compound as a red-brown crystal. This crude crystal was recrystallized from diethyl ether-petroleum ether and dried by a hot air drier to obtain 5.7 g (yield: 51.3%) of the title compound as a pale yellow crystal. the mixture was dissolved the resulting solution was stirred for 1 hour with stirring under ice cooling After the dropwise addition the solution was stirred under ice cooling for 1 hour by stirring for 2 hours The obtained reaction solution the precipitated crystal was collected by filtration washed with 10 mL of water dried by a hot air drier to obtain 8.4 g of the crude crystal of the title compound as a red-brown crystal This crude crystal was recrystallized from diethyl ether-petroleum ether dried by a hot air drier

Conditions: temp:2.51; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 120 ml of water and 15 ml of 35% hydrochloric acid were added to 5.6 g (0.06 mole) of aniline to obtain a solution. The solution was ice-cooled to 0 to 5° C. Thereto was drop-wise added, with stirring, 24 ml of water in which 4.2 g (0.06 mole) of sodium nitrite had been dissolved, after which stirring was conducted for 1 hour. Then, this aqueous diazonium salt solution was dropwise added to 120 ml of a pyridine solution containing 10.2 g (0.06 mole) of diethyl α-cyanosuccinate, with stirring under ice-cooling. After the dropwise addition, the mixture was stirred for 1 hour under ice-cooling and successively for 1 hour at room temperature, to give rise to a reaction. After the reaction, 240 ml of a 2% aqueous sodium hydroxide solution was added, followed by stirring for 2 hours. Then, the reaction mixture was drop-wise added to 240 ml of 35% hydrochloric acid under ice-cooling. The resulting crystals were collected by filtration, washed with 10 ml of water, and dried in a hot-air drier, to obtain 8.4 g of crude, reddish brown crystals of title compound. The crude crystals were recrystallized from diethyl ether-petroleum ether and dried in a hot-air drier, to obtain 5.7 g (yield: 51.3%) of a title compound as light yellow crystals. to obtain a solution added after which stirring with stirring under ice- cooling After the dropwise addition the mixture was stirred for 1 hour under ice- cooling and successively for 1 hour at room temperature to give rise to a reaction was added by stirring for 2 hours cooling The resulting crystals were collected by filtration washed with 10 ml of water dried in a hot-air drier, to obtain 8.4 g of crude