1,1,1-trifluoro-3-methylbut-2-ene

Conditions: temp:43.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1,1,1-Trifluoro-3-methyl-2-butene (16.1 g, 130 mmol), sodim cyanide (6.7 g, 133 mmol), and water (3.1 g) were stirred together in a flask, and cooled in an ice-salt mixture to 1°-6° C. internal temperature. Sulphuric acid (35.3 g of 98%, 353 mmol) was added from a dropping funnel over 45 minutes. After the addition, the cooling bath was removed, and the reaction mixture allowed to warm. A temperature of 35° C. was reached in 12 minutes, and cooling was applied to give 25° C. When the heat of reaction had subsided, the mixture was heated in a water bath to 43° C. during 2 hours and kept at 43° C. for 1.75 hours. The mixture was allowed to cool to 20° C., and the apparatus was then evacuated to 15 mmHg through a -78° C. trap. The mixture was then cooled to 5°-10° C. in a bath of ice and salt, while water (46 ml) was added over 10 minutes from the dropping funnel. The mixture at 25° C. was stirred vigorously and again evacuated to 15 mmHg, to collect unreacted olefin and other volatile products in the -78° C. trap. After the addition the cooling bath was removed to warm cooling to give 25° C When the heat of reaction kept at 43° C. for 1.75 hours to cool to 20° C. the apparatus was then evacuated to 15 mmHg through a -78° C. trap The mixture was then cooled to 5°-10° C. in a bath of ice and salt, while water (46 ml) was added over 10 minutes from the dropping funnel again evacuated to 15 mmHg to collect unreacted olefin and other volatile products in the -78° C. trap

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

Procedure: The reaction mixture was distilled at ca. 65 mmHg pressure until 70 g of condensate had been collected; further distillate when examined by g.l.c. (2 m silicone, 50°) contained none of the required azide. The distillate was added to ice water (500 ml), shaken, and the lower organic layer (17.1 g) separated, shaken with an excess of aqueous sodium bicarbonate solution, then with water, and dried (Na2SO4). The washings were added to the ice-water layer, which was then extracted three times with ether. The combined ether extracts were washed with an excess of aqueous sodium bicarbonate solution, then with water and dried. The ether was removed to leave a residue of the azide concentrate (13.0 g). The azide was not isolated in the pure state, but as a precaution was handled diluted with ether, olefin and unchanged bromo-compound. The separated organic layer (17.1 g, above) by g.l.c. (2 m silicone, 50°) contained 1,1,1-trifluoro-3-methyl-2-butene (27%), 3-bromo-1,1,1-trifluoro-3-methylbutane (17%) and the azide. The product yields estimated by g.l.c. were 3-azide-1,1,1-trifluoro-3-methylbutane (10.0 g, 15%), 1,1,1-trifluoro-3-methyl-2-butene (27.5 g, 55%), and 3-bromo-1,1,1-trifuloro-3-methylbutane unreacted (4.4 g, 5%). The remaining material was partly accounted for as 1,1,1-trifluoro-3-methyl-2-butene in the ether distillate. The reaction mixture was distilled at ca. 65 mmHg pressure until 70 g of condensate had been collected (2 m silicone, 50°) The distillate was added to ice water (500 ml) the lower organic layer (17.1 g) separated shaken with an excess of aqueous sodium bicarbonate solution with water, and dried (Na2SO4) The washings were added to the ice-water layer, which was then extracted three times with ether The combined ether extracts were washed with an excess of aqueous sodium bicarbonate solution with water and dried The ether was removed to leave a residue of the azide concentrate (13.0 g) The azide was not isolated in the pure state The product yields