1,2-dibromo-1-chloro-1,2,2-trifluoroethane

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

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

Procedure: A new method to prepare the desired 3,4,4-trifluoro-3-butenoic acid (IV) involves a one pot reaction of 1-chloro-1,2-dibromotrifluoroethane (VI) or 1,1,2-trichloretrifluoroethane (X) with vinylidene chloride in the presence of ammonium persulfate/sodium formate/air in DMF to give directly 4-bromo-3-chloro-3,4,4-trifluorobutanoic acid (VIII) or novel compound 3,4-dichloro-3,4,4-trifluoro-butanoic acid (XI). The reaction conditions to prepare XI from X are similar to those described in Hu, Chang-Ming; Qing, Feng-Ling; Zhang, Hong-Gen; J. Fluorine Chem., 1990, (49) 275-280. The formation of XI in the above reaction was confirmed by GC/MS (EI): m/z 212 (M+ 2), 210 (M+), 195, 193, 157, 155, 127, 125, 107, 105, 89, 69, 45. Dehalogenation of VIII or XI with zinc gives IV. ##STR6##

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

Procedure: A one pot reaction of 1-chloro-1,2-dibromotrifluoroethane (VI) or 1,1,2-trichlorotrifluoroethane (X) with vinylidene chloride in the presence of ammonium persulfate/sodium formate/air in DMF to give 4-bromo-3-chloro-3,4,4-trifluorobutanoic acid (VIII) or 3,4- dichloro-3,4,4-trifluorobutanoic acid (XI).

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

Procedure: A one pot reaction of 1-chloro-1,2-dibromotrifluoroethane (VI) or 1,1,2-trichlorotrifluoroethane (X) with vinylidene chloride in the presence of ammonium persulfate/sodium formate/air in DMF to give 4-bromo-3-chloro-3,4,4-trifluorobutanoic acid (VIII) or 3,4- dichloro-3,4,4-trifluorobutanoic acid (XI).

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

Procedure: A one pot reaction of 1-chloro-1,2-dibromotrifluoroethane (VI) with ethyl vinyl ether in the presence of sodium hydrosulfite/sodium bicarbonate followed by oxidation of the intermediate, 4-bromo-3-chloro-3,4,4-trifluorobutanal (VII), without isolation, with sodium chlorite/hydrogen peroxide to give 4-bromo-3-chloro-3,4,4-trifluorobutanoic acid (VIII) in overall unexpected yields;

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

Procedure: A mixture of 1,1,2-trichlorotrifluoroethane (X) (9.37 g, 50 mmol), vinylidene chloride (4.85 g, 50 mmol), ammonium persulfate (11.41 g, 50 mmol), sodium formate (3.4 g, 50 mmol) and water (1.8 g, 0.1 mol) in DMF (80 mL.) was stirred (dry-ice/acetone condensor) at room temperature with air bubbling. After 30 min, an aliquot of the reaction mixture was acidified with dilute HCl, extracted with ether and analyzed by GC, which indicated the formation of two products. These products were identified by GC/MS (EI) as 4-chloro-3,4,4-trifluoro-2-butenoic acid and novel compound 3,4-dichloro-3,4,4-trifluorobutanoic acid (XI). The compound XI gives 3,4,4-trifluoro-3-butenoic add (IV) upon reaction with zinc. Under the above reaction conditions, 1-chloro-1,2-dibromotrifluoroethane (VI) gave 3-chloro-4-bromo-3,4,4-trifluorobutanoic acid (VIII) as one of the products.

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

Procedure: A one pot reaction of 1-chloro-1,2-dibromotrifluoroethane (VI) or 1,1,2-trichlorotrifluoroethane (X) with vinylidene chloride in the presence of ammonium persulfate/sodium formate/air in DMF to give 4-bromo-3-chloro-3,4,4-trifluorobutanoic acid (VIII) or 3,4-dichloro-3,4,4-trifluorobutanoic acid (XI).

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

Procedure: A one pot reaction of 1-chloro-1,2-dibromotrifluoroethane (VI) or 1,1,2-trichlorotrifluoroethane (X) with vinylidene chloride in the presence of ammonium persulfate/sodium formate/air in DMF to give 4-bromo-3-chloro-3,4,4-trifluorobutanoic acid (VIII) or 3,4-dichloro-3,4,4-trifluorobutanoic acid (XI).

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

Procedure: A one pot reaction of 1-chloro-1,2-dibromotrifluoroethane (VI) with ethyl vinyl ether in the presence of sodium hydrosulfite/sodium bicarbonate followed by oxidation of the intermediate, 4-bromo-3-chloro-3,4,4-trifluorobutanal (VII), without isolation, with sodium chlorite/hydrogen peroxide to give 4-bromo-3-chloro-3,4,4-trifluorobutanoic acid (VIII) in overall unexpected yields;

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

Procedure: A one pot reaction of 1-chloro-1,2-dibromotrifluoroethane (VI) with ethyl vinyl ether in the presence of sodium hydrosulfite/sodium bicarbonate followed by oxidation of the intermediate, 4-bromo-3-chloro-3,4,4-trifluorobutanal (VII), without isolation, with sodium chlorite/hydrogen peroxide to give 4-bromo-3-chloro-3,4,4-trifluorobutanoic acid (VIII) in overall unexpected yields;

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

Procedure: A one pot reaction of 1-chloro-1,2-dibromotrifluoroethane (VI) or 1,1,2-trichlorotrifiuoroethane (X) with vinylidene chloride in the presence of ammoninm persulfate/sodium formate/air in DMF to give 4-bromo-3-chloro-3,4,4-trifiuorobutanoic acid (VIII) or 3,4- dichloro-3,4,4-trifluorobutanoic acid (XI).

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

Procedure: A one pot reaction of 1-chloro-1,2-dibromotrifluoroethane (VI) with ethyl vinyl ether in the presence of sodium hydrosulfite/sodium bicarbonate followed by oxidation of the intermediate, 4-bromo-3-chloro-3,4,4-trifluorobutanal (VII), without isolaton, with sodium chlorite/hydrogen peroxide to give 4-bromo-3-chloro-3,4,4-trifiuorobutanoic acid (VIII) in overall unexpected yields;