| production method | 75g(0.446mol)4,5-dicyano-1, 3-dithiacyclopentene -2-one and 75g sand are put into a 200ml round bottom flask, the bottleneck is connected with a small quartz tube of 2cm * 0.5cm, and the upper end is connected in series with two cold traps. The cold trap (1) is equipped with an electromagnetic stirring rod, placed in a dry ice-acetone cold bath, and the cold trap (2) is cooled with liquid nitrogen. After the complete set of instruments is placed on the protective screen, the quartz tube is heated to 800 ℃ with a temperature control device, and the oil pump is decompressed to about 0.27kpa. Put the flask in an air bath to raise the temperature to about 135 ℃, the pressure rises to about 0.4~0.67kpa for 1~2h, and when the pressure drops to about 0.27kpa, the material in the trap (1) is suddenly distilled into another trap cooled by dry ice-acetone under stirring and decompression. During distillation, the trap (1) is heated with a hot water bath to control the pressure to prevent the distillation from being too fast, causing the dicyanide formula to condense in the trap (1). 20~26g of product (50% ~ 76%) was obtained, usually containing less than 0.1% carbon disulfide and 0.5% ~ 1% benzene. Carbon disulfide can be removed by effective fractionation, and benzene can be separated by chromatography. |
