(4-bromo-2-chloro-5-fluorophenyl)methanol

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

Procedure: To a solution of (4-bromo-2-chloro-5-fluorophenyl)methanol (5.00 g, 21.00 mmol) in dichloromethane (150 mL) was added phosphorous tribromide (8.53 g, 31.50 mmol) at 0° C. The clear reaction solution was stirred at the same temperature for 1 hour, then at an ambient temperature for 2 hours. The reaction mixture was concentrated in vacuo to dryness to obtain viscous yellow liquid which was added to a stirred mixture of cyclohexanol (1.68 g, 16.80 mmol) and sodium hydride (60% dispersion in mineral oil, 1.93 g, 21.00 mmol,) in N,N-dimethylformamide (15 mL) at 0° C. The reaction mixture was stirred at ambient temperature for 16 hours and quenched with addition of saturated ammonium chloride (100 mL). The organic layer was extracted with ethyl acetate (3×50 mL). The combined organic layers were dried over anhydrous sodium sulfate and filtered the solid. The filtrate was concentrated in vacuo to dryness. The residue was purified by flash column chromatography with ethyl acetate in hexanes (10%) to afford the title compound (2.60 g, 38%) as a viscous liquid: MS (ES+) m/z 320.9, 318.9 (M+1). at an ambient temperature for 2 hours The reaction mixture was concentrated in vacuo to dryness to obtain viscous yellow liquid which The reaction mixture was stirred at ambient temperature for 16 hours quenched with addition of saturated ammonium chloride (100 mL) The organic layer was extracted with ethyl acetate (3×50 mL) The combined organic layers were dried over anhydrous sodium sulfate filtered the solid The filtrate was concentrated in vacuo to dryness The residue was purified by flash column chromatography with ethyl acetate in hexanes (10%)

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

Procedure: To a solution of (4-bromo-2-chloro-5-fluorophenyl)methanol (3.95 g, 16.49 mmol) and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) (0.5 mL, 3.34 mmol) in methylene chloride (30 mL) was added trichloroacetonitrile (, 2.50 mL, 24.93 mmol) over 5 min at 0° C., stirring was continued for 4 h at 0° C. After concentrated in vacuo, the residue was purified by column chromatography eluting with 5% ethyl acetate in hexanes to give 4-bromo-2-chloro-5-fluorobenzyl 2,2,2-trichloroacetimidate as a colorless solid (5.80 g, 91%): δ 8.49 (s, 1H), 7.59 (d, J=6.3 Hz, 1H), 7.32 (d, J=9.0 Hz, 1H), 5.37 (s, 2H). After concentrated in vacuo the residue was purified by column chromatography eluting with 5% ethyl acetate in hexanes

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of methyl 4-bromo-2-chloro-5-fluorobenzoate (18.00 g, 67.28 mmol) in tetrahydrofuran (100 mL) was added methanol (3.0 mL, 74.15 mmol), followed by the addition of lithium borohydride solution (4.0 M in tetrahydrofuran, 33.7 mL, 134.80 mmol) at 0° C. over 30 min. The reaction mixture was stirred for further 10 min at 0° C., and then at ambient temperature for 20 h; 5% sodium hydroxide solution (100 mL) was added to the reaction mixture slowly at 0° C. After stirring for 30 min. the reaction mixture was extracted with ethyl acetate (200 mL×3). The organic layer was washed with brine, and concentrated in vacuo to afford the title compound as a pale yellow solid (16.00 g, 99%): 1H NMR (300 MHz, CDCl3) δ 7.51 (d, J=6.0 Hz, 1H), 7.30 (d, J=9.0 Hz, 1H), 4.69 (s, 2H), 2.08 (s, 1H). at ambient temperature for 20 h After stirring for 30 min. the reaction mixture was extracted with ethyl acetate (200 mL×3) The organic layer was washed with brine concentrated in vacuo

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

Procedure: To a solution of (4-bromo-2-chloro-5-fluorophenyl)methanol (3.95 g, 16.49 mmol) and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) (0.5 mL, 3.34 mmol) in methylene chloride (30 mL) was added trichloroacetonitrile (, 2.50 mL, 24.93 mmol) over 5 min at 0° C., stirring was continued for 4 h at 0° C. After concentrated in vacuo, the residue was purified by column chromatography eluting with 5% ethyl acetate in hexanes to give 4-bromo-2-chloro-5-fluorobenzyl 2,2,2-trichloroacetimidate as a colorless solid (5.80 g, 91%): δ 8.49 (s, 1H), 7.59 (d, J=6.3 Hz, 1H), 7.32 (d, J=9.0 Hz, 1H), 5.37 (s, 2H). After concentrated in vacuo the residue was purified by column chromatography eluting with 5% ethyl acetate in hexanes

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of methyl 4-bromo-2-chloro-5-fluorobenzoate (18.00 g, 67.28 mmol) in tetrahydrofuran (100 mL) was added methanol (3.0 mL, 74.15 mmol), followed by the addition of lithium borohydride solution (4.0 M in tetrahydrofuran, 33.7 mL, 134.80 mmol) at 0° C. over 30 min. The reaction mixture was stirred for further 10 min at 0° C., and then at ambient temperature for 20 h; 5% sodium hydroxide solution (100 mL) was added to the reaction mixture slowly at 0° C. After stirring for 30 min. the reaction mixture was extracted with ethyl acetate (200 mL×3). The organic layer was washed with brine, and concentrated in vacuo to afford the title compound as a pale yellow solid (16.00 g, 99%): 1H NMR (300 MHz, CDCl3) δ 7.51 (d, J=6.0 Hz, 1H), 7.30 (d, J=9.0 Hz, 1H), 4.69 (s, 2H), 2.08 (s, 1H). at ambient temperature for 20 h After stirring for 30 min. the reaction mixture was extracted with ethyl acetate (200 mL×3) The organic layer was washed with brine concentrated in vacuo