ethyl 4,4-difluorocyclohexane-1-carboxylate

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

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

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

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

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 lithium aluminum hydride (2.6 g, 69 mmol) in diethyl ether (160 mL,) was added slowly a solution of commercially available ethyl 4,4-difluorocyclohexanecarboxylate (Matrix, 11.0 g, 57 mmol) in diethyl ether (20 mL). The reaction mixture was refluxed for 4 hours, then cooled in an ice bath, quenched cautiously with sequential addition of water (2.6 mL.), 15% NaOH (2.6 mL) and water (7.8 mL) and extracted with ethyl acetate (3×100 mL). The mixture was filtered and concentrated to afford the title compound. The reaction mixture was refluxed for 4 hours cooled in an ice bath quenched cautiously with sequential addition of water (2.6 mL.), 15% NaOH (2.6 mL) and water (7.8 mL) extracted with ethyl acetate (3×100 mL) The mixture was filtered concentrated

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

Procedure: To a suspension of lithium aluminum hydride (2.6 g, 69 mmol) in diethyl ether (160 mL,) was added slowly a solution of commercially available ethyl 4,4-difluorocyclohexanecarboxylate (Matrix, 11.0 g, 57 mmol) in diethyl ether (20 mL). The reaction mixture was refluxed for 4 hours, then cooled in an ice bath, quenched cautiously with sequential addition of water (2.6 mL.), 15% NaOH (2.6 mL) and water (7.8 mL) and extracted with ethyl acetate (3×100 mL). The mixture was filtered and concentrated to afford the title compound. The reaction mixture was refluxed for 4 hours cooled in an ice bath quenched cautiously with sequential addition of water (2.6 mL.), 15% NaOH (2.6 mL) and water (7.8 mL) extracted with ethyl acetate (3×100 mL) The mixture was filtered concentrated

Conditions: temp:60.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A suspension of ethyl 4,4-difluorocyclohexanecarboxylate (2500 mg, 13 mmol) in ammonium hydroxide (28%, 50 ml) was stirred at 60° C. overnight. After removal of solvent, the residue was washed with water. The precipitate was obtained as product (white solid, 800 mg). 1H NMR (300 MHz, CDCl3): δ 5.31-5.45 (br, 2H), 2.02-2.27 (m, 3H), 1.92-2.02 (m, 2H), 1.72-1.87 (m, 4H). The mother liquor was acidified with 1N HCl to pH<1. The compound was extracted with EtOAc. The organic layer was washed with water, brine, dried over anhydrous sodium sulphate, filtered, condensed. 4,4-difluorocyclohexanecarboxylic acid was obtained as a 1200 mg of white solid which was further converted to 4,4-difluorocyclohexanecarboxamide by following procedure. After removal of solvent the residue was washed with water The precipitate was obtained as product (white solid, 800 mg) The compound was extracted with EtOAc The organic layer was washed with water, brine dried over anhydrous sodium sulphate filtered condensed

Conditions: temp:60.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A suspension of ethyl 4,4-difluorocyclohexanecarboxylate (2500 mg, 13 mmol) in ammonium hydroxide (28%, 50 ml) was stirred at 60° C. overnight. After removal of solvent, the residue was washed with water. The precipitate was obtained as product (white solid, 800 mg). 1H NMR (300 MHz, CDCl3): δ 5.31-5.45 (br, 2H), 2.02-2.27 (m, 3H), 1.92-2.02 (m, 2H), 1.72-1.87 (m, 4H). The mother liquor was acidified with 1N HCl to pH<1. The compound was extracted with EtOAc. The organic layer was washed with water, brine, dried over anhydrous sodium sulphate, filtered, condensed. 4,4-difluorocyclohexanecarboxylic acid was obtained as a 1200 mg of white solid which was further converted to 4,4-difluorocyclohexanecarboxamide by following procedure. After removal of solvent the residue was washed with water The precipitate was obtained as product (white solid, 800 mg) The compound was extracted with EtOAc The organic layer was washed with water, brine dried over anhydrous sodium sulphate filtered condensed

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

Procedure: A solution of ethyl 4,4-difluorocyclohexanecarboxylate (0.385 g, 2.003 mmol) in THF (12 mL) was treated with H2O (6 mL) followed by lithium hydroxide monohydrate (0.420 g, 10.02 mmol) and the mixture stirred vigorously at RT overnight. The mixture was treated with EtOAc, acidified with 1M HCl until pH 4, the layers separated and the aqueous layer extracted with additional EtOAc (1×). The combined organics were washed with brine, dried over MgSO4 and concentrated to dryness to afford 4,4-difluorocyclohexanecarboxylic acid (318 mg, 97%) as a white solid. 1H NMR (400 MHz, DMSO-d6): δ 12.28 (s, 1H), 2.40 (m, 1H), 2.02-1.75 (m, 6H), 1.59 (m, 2H). the layers separated the aqueous layer extracted with additional EtOAc (1×) The combined organics were washed with brine dried over MgSO4 concentrated to dryness

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

Procedure: A solution of ethyl 4,4-difluorocyclohexanecarboxylate (0.385 g, 2.003 mmol) in THF (12 mL) was treated with H2O (6 mL) followed by lithium hydroxide monohydrate (0.420 g, 10.02 mmol) and the mixture stirred vigorously at RT overnight. The mixture was treated with EtOAc, acidified with 1M HCl until pH 4, the layers separated and the aqueous layer extracted with additional EtOAc (1×). The combined organics were washed with brine, dried over MgSO4 and concentrated to dryness to afford 4,4-difluorocyclohexanecarboxylic acid (318 mg, 97%) as a white solid. 1H NMR (400 MHz, DMSO-d6): δ 12.28 (s, 1H), 2.40 (m, 1H), 2.02-1.75 (m, 6H), 1.59 (m, 2H). the layers separated the aqueous layer extracted with additional EtOAc (1×) The combined organics were washed with brine dried over MgSO4 concentrated to dryness

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

Procedure: A solution of triethylamine trihydrofluoride (0.479 mL, 2.94 mmol) in DCE (6 mL) at RT was treated with XtalFluor-M (1.071 g, 4.41 mmol) followed by ethyl 4-oxocyclohexanecarboxylate (0.500 g, 2.94 mmol) and the mixture heated to reflux for 2.5 h. The mixture was cooled to RT, treated with satd. NaHCO3 and stirred overnight. The mixture was diluted with DCM, the layers separated, the aqueous layer extracted with additional DCM (1×) and the combined organics were dried over MgSO4 and filtered through a small pad of silica gel, rinsing well with DCM. The filtrate was concentrated to dryness and purified via silica gel chromatography (DCM/Hex) to afford ethyl 4,4-difluorocyclohexanecarboxylate (390 mg, 69%) as a colorless oil. 1H NMR (400 MHz, DMSO-d6): δ 4.05 (q, J=7.1 Hz, 2H), 2.49 (m, 1H), 2.02-1.77 (m, 6H), 1.65-1.50 (m, 2H), 1.16 (t, J=7.1 Hz, 3H). the mixture heated to reflux for 2.5 h treated with satd the layers separated the aqueous layer extracted with additional DCM (1×) the combined organics were dried over MgSO4 filtered through a small pad of silica gel rinsing well with DCM The filtrate was concentrated to dryness purified via silica gel chromatography (DCM/Hex)