1,1-difluoroethene

Conditions: temp:0.00; pressure:0.00; stir:

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

Procedure: To a suspension of 4.4 g of lithium wire cut into small pieces in 200 mL of anhydrous THF stirred under argon and cooled on ice (internal temperature <10° C.) was added dimethylphenyl-chlorosilane in 5 mL portions over 1 hour. The deep red color of the silyl lithium reagent appeared after approximately 0.75 hour. The mixture was stirred on ice for an additional 5 hours (internal temperature remained between 5° C. and 10° C.). The mixture was cooled on a dry ice/acetone bath and 1,1-difluoroethylene was introduced by filling a balloon connected to the reaction mixture and the reagent cylinder using a three-way valve. The balloon was filled with 1,1-difluoroethylene and emptied into the reaction mixture 10 times. The mixture was allowed to warm to room temperature (effervescence observed, probably from unreacted 1,1-difluoroethylene). The mixture was diluted with 200 mL of hexanes and filtered through a cotton wool plug. The filtrate was washed with water, dried, filtered, and concentrated in vacuo. Four fractional distillations under vacuum through a Vigreux column gave 4.6 g of product. cooled on ice (internal temperature <10° C.) The mixture was stirred on ice for an additional 5 hours (internal temperature remained between 5° C. and 10° C.) The mixture was cooled on a dry ice/acetone bath filtered through a cotton wool plug The filtrate was washed with water dried filtered concentrated in vacuo

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

Procedure: As another example, 2-trifluoromethyl-1,1,1,4,4-pentafluorobutane may be prepared by reacting commercially available 1,1-difluoroethylene according to the procedure of George L. Fleming et al., supra, to form a product which may then be hydrogenated to form 2-trifluoromethyl-1,1,1,2,4,4-hexafluorobutane which may then be dehydrohalogenated and then hydrogenated to form 2-trifluoromethyl-1,1,1,4,4-pentafluorobutane Fleming et al., supra, to form a product which

Conditions: temp:0.00; pressure:0.00; stir:

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

Procedure: As another example, 2-trifluoromethyl-1-chloro-1,1,2,4,4-pentafluorobutane may be prepared by reacting commercially available 1,1-difluoroethylene according to the procedure of George L. Fleming et al., supra, to form a product which may then be hydrogenated to form 2-trifluoromethyl-1,1,1,2,4,4-hexafluorobutane which may then be chlorinated to form 2-trifluoromethyl-1-chloro-1,1,2,4,4-pentafluorobutane. Fleming et al., supra, to form a product which

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

Procedure: As another example, 2-trifluoromethyl-1-chloro-1,1,2,4,4-pentafluorobutane may be prepared by reacting commercially available 1,1-difluoroethylene according to the procedure of George L. Fleming et al., supra, to form a product which may then be hydrogenated to form 2-trifluoromethyl-1,1,1,2,4,4-hexafluorobutane which may then be chlorinated to form 2-trifluoromethyl-1-chloro-1,1,2,4,4-pentafluorobutane. Fleming et al., supra, to form a product which

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

Procedure: As noted above, we prefer to cover at least a portion of the sensor section (102), distal section (104), mid-section (106), or proximal section (108) with a fluoropolymeric composition comprising a copolymer of tetrafluoroethylene, hexafluoropropylene, and vinylidene fluoride or an alloy or mixture of the three. Especially suitable are the series of fluoroplastics known as "THV Fluoroplastics" produced by 3M, particularly THV 200, THV 300, THV 400, and THV 500. Preferred compositions include those which have a melting range between about 115° and 180° C. (by DSC), a melt flow index of 5 to 25 (ASTM 1238), a specific gravity of 1.95-1.98 g/cc (ASTM 792), and elongation at breakage of 500-600% (ASTM 638). Such polymeric compositions are shown, for other uses, in U.S. Pat. No. 4,991,932, U.S. Pat. No. 4,979,799, U.S. Pat. No. 4,986,630, to Herbrects et al; U.S. Pat. No. 4,829,116, and U.S. Pat. No. 4,556,589. The polymeric composition is preferably placed onto the catheter by first extruding the polymeric composition into suitably sized tubing, at least partially cross-linking the polymer (often using radiation such as electron beam), placing the polymer about the catheter, and heating the polymer to shrink it onto the catheter body. an alloy or mixture of the three

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

Procedure: As another example, 2-trifluoromethyl-1,1,1,4,4-pentafluorobutane may be prepared by reacting commercially available 1,1-difluoroethylene according to the procedure of George L. Fleming et al., supra, to form a product which may then be hydrogenated to form 2-trifluoromethyl-1,1,1,2,4,4-hexafluorobutane which may then be dehydrohalogenated and then hydrogenated to form 2-trifluoromethyl-1,1,1,4,4-pentafluorobutane. Fleming et al., supra, to form a product which

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

Procedure: To a solution of lithium wire (2.08 g, 300 mmol) in dry tetrahydrofuran (150 ml) was added methyldiphenylsilyl chloride (15.8 ml, 75 mmol) and a catalytic amount of iodine. The reaction mixture was sonicated for 40 min and then stirred overnight at room temperature. The reaction mixture was cooled to −78° C. and 1,1-difluoroethylene (approx. 225 mmol) was passed through the mixture for 30 min. The mixture was stirred at −78° C. for 2 h and then warmed to room temperature. The reaction mixture was sonicated for 40 min The reaction mixture was cooled to −78° C. The mixture was stirred at −78° C. for 2 h warmed to room temperature

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

Procedure: As another example, 2-trifluoromethyl-1,1,1,4,4-pentafluorobutane may be prepared by reacting commercially available 1,1-difluoroethylene according to the procedure of George L. Fleming et al., supra, to form a product which may then be hydrogenated to form 2-trifluoromethyl-1,1,1,2,4,4-hexafluorobutane which may then be dehydrohalogenated and then hydrogenated to form 2-trifluoromethyl-1,1,1,4,4-pentafluorobutane. Fleming et al., supra, to form a product which

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

Procedure: As another example, 2-trifluoromethyl-1,1,1,4,4-pentafluorobutane may be prepared by reacting commercially available 1,1-difluoroethylene according to the procedure of George L. Fleming et al., supra, to form a product which may then be hydrogenated to form 2-trifluoromethyl-1,1,1,2,4,4-hexafluorobutane which may then be dehydrohalogenated and then hydrogenated to form 2-trifluoromethyl-1,1,1,4,4-pentafluorobutane. Fleming et al., supra, to form a product which

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

Procedure: To a solution of lithium wire (2.08 g, 300 mmol) in dry tetrahydrofuran (150 ml) was added methyldiphenylsilyl chloride (15.8 ml, 75 mmol) and a catalytic amount of iodine. The reaction mixture was sonicated for 40 min and then stirred overnight at room temperature. The reaction mixture was cooled to −78° C. and 1,1-difluoroethylene (approx. 225 mmol) was passed through the mixture for 30 min. The mixture was stirred at −78° C. for 2 h and then warmed to room temperature. The reaction mixture was quenched with saturated ammonium chloride solution and extracted with cyclohexane (×2). The combined extracts were washed with brine, dried (MgSO4) and concentrated in vacuo. The residue was purified by column chromatography (silica, 1 kg) eluting with hexane, followed by cyclohexane. The appropriate fractions were combined and concentrated to give Preparation 83 (7 g) as a colourless oil. The reaction mixture was sonicated for 40 min The reaction mixture was cooled to −78° C. The mixture was stirred at −78° C. for 2 h warmed to room temperature The reaction mixture was quenched with saturated ammonium chloride solution extracted with cyclohexane (×2) The combined extracts were washed with brine dried (MgSO4) concentrated in vacuo The residue was purified by column chromatography (silica, 1 kg) eluting with hexane concentrated to give