1,2-dichloro-1,1-difluoroethane

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Ex-18a) A solution of N-Boc-D,L-homocysteine (5 mmol) in NaOH (5 mL, 2N) was slowly added to a stirred solution of 1,2-dichloro-1,1-difluoroethane (5 mmol) in DMF. The resulting solution was then warmed to 50° C. for 16 hours. The reaction solution was then poured onto EtOAc and extracted with citric acid (5%) and brine, dried (Na2SO4) and concentrated in vacuo. The material was purified by flash column chromatography to yield N-Boc-S-(2-chloro-1,1-difluoroethyl)-D,L-homocysteine. Example 18 is prepared in the same manner as described for Example 17 starting with N-Boc-S-(2-chloro-1,1-difluoroethyl)-D,L-homocysteine. The reaction solution was then poured onto EtOAc extracted with citric acid (5%) and brine dried (Na2SO4) concentrated in vacuo The material was purified by flash column chromatography

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

Procedure: 2.5 g (22.9 mmol) of p-aminophenol, 3.09 g (22.9 mmol) of 1,2-dichloro-1,1-difluoroethane, 5.48 g (39.6 mmol) of K2CO3 and 40 ml of dry acetonitrile were stirred together at room temperature for 5 days. The mixture was poured into water and extracted two times into ether. The combined ether extracts were washed with water, dried over MgSO4 and filtered: HCl gas was bubbled into the ether solution causing the above-named aniline to precipitate as the hydrochloride salt, which was collected by filtration and recrystallized twice from CH3CN to give 0.9 g (16 percent of theoretical d 245°-250° C.) of a white solid. extracted two times into ether The combined ether extracts were washed with water dried over MgSO4 filtered HCl gas was bubbled into the ether solution to precipitate as the hydrochloride salt, which was collected by filtration recrystallized twice from CH3CN to give 0.9 g (16 percent of theoretical d 245°-250° C.) of a white solid

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

Procedure: An alternative approach to HCFC's is the chlorination of fluorocarbons such as CH3CF3 (HFC-143a). For example, McBee (Industrial and Engineering Chemistry, Vol. 39, pp. 409-412 (1947)) reported that vapor phase chlorination of HFC-143a afforded a mixture of HCFC-133a, HCFC-132b, CHCl2CF3 (HCFC-123), and the fully chlorinated CF3CCl3 (CFC-113a). McBee also reported the chlorination of CH3CClF2 (HCFC-142b) to give HCFC-132b, HCFC-122, and the fully chlorinated CClF2CCl3 (CFC-112a). Again, using this technique --CH2Cl and --CHCl2 groups dominate the attainable substitution pattern. afforded