Diethyl (4-Fluorobenzyl)phosphonate

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

Conditions: temp:150.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4-fluorobenzyl bromide (100 g) and triethyl phosphite (120 ml) were mixed, and the mixture was stirred at 150° C., for 22 hours. The obtained reaction mixture was distilled under reduced pressure (bp 115-120° C./1.5 mmHg) to give diethyl 4-fluorobenzylphosphonate (125 g). To a solution of 4-fluorobenzylphosphonate (60.8 g), 15-Crown-5 (4 ml) in THF (400 ml) was added 60% sodium hydride in mineral oil (9.75 g) under ice cooling with stirring, and the mixture was stirred at the same temperature for 30 minutes. To the mixture was added dropwise a solution of 1-tert-butoxycarbonyl-4-piperidone (42.0 g) in THF (150 ml) under ice cooling, and the mixture was stirred at room temperature for 22 hours. After the addition of water under ice cooling, the mixture was extracted with ethyl acetate, and the organic layer was washed with saturated aqueous solution of sodium hydrogencarbonate, saturated aqueous solution of sodium chloride, successively. The organic layer was dried over magnesium sulfate and concentrated under reduced pressure. The concentrate was subjected to column chromatography (silica gel 650 g, hexane/ethyl acetate=30/1 to 10/1), and the desired fraction was concentrated under reduced pressure to give 1-tert-butoxycarbonyl-4-(4-fluorobenzylidene)piperidine (47.0 g). The obtained reaction mixture was distilled under reduced pressure (bp 115-120° C./1.5 mmHg)

Conditions: temp:150.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4-fluorobenzyl bromide (100 g) and triethyl phosphite (120 ml) were mixed, and the mixture was stirred at 150° C., for 22 hours. The obtained reaction mixture was distilled under reduced pressure (bp 115-120° C./1.5 mmHg) to give diethyl 4-fluorobenzylphosphonate (125 g). To a solution of 4-fluorobenzylphosphonate (60.8 g), 15-Crown-5 (4 ml) in THF (400 ml) was added 60% sodium hydride in mineral oil (9.75 g) under ice cooling with stirring, and the mixture was stirred at the same temperature for 30 minutes. To the mixture was added dropwise a solution of 1-tert-butoxycarbonyl-4-piperidone (42.0 g) in THF (150 ml) under ice cooling, and the mixture was stirred at room temperature for 22 hours. After the addition of water under ice cooling, the mixture was extracted with ethyl acetate, and the organic layer was washed with saturated aqueous solution of sodium hydrogencarbonate, saturated aqueous solution of sodium chloride, successively. The organic layer was dried over magnesium sulfate and concentrated under reduced pressure. The concentrate was subjected to column chromatography (silica gel 650 g, hexane/ethyl acetate=30/1 to 10/1), and the desired fraction was concentrated under reduced pressure to give 1-tert-butoxycarbonyl-4-(4-fluorobenzylidene)piperidine (47.0 g). The obtained reaction mixture was distilled under reduced pressure (bp 115-120° C./1.5 mmHg)

Conditions: temp:150.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4-fluorobenzyl bromide (100 g) and triethyl phosphite (120 ml) were mixed, and the mixture was stirred at 150° C., for 22 hours. The obtained reaction mixture was distilled under reduced pressure (bp 115-120° C./1.5 mmHg) to give diethyl 4-fluorobenzylphosphonate (125 g). To a solution of 4-fluorobenzylphosphonate (60.8 g), 15-Crown-5 (4 ml) in THF (400 ml) was added 60% sodium hydride in mineral oil (9.75 g) under ice cooling with stirring, and the mixture was stirred at the same temperature for 30 minutes. To the mixture was added dropwise a solution of 1-tert-butoxycarbonyl-4-piperidone (42.0 g) in THF (150 ml) under ice cooling, and the mixture was stirred at room temperature for 22 hours. After the addition of water under ice cooling, the mixture was extracted with ethyl acetate, and the organic layer was washed with saturated aqueous solution of sodium hydrogencarbonate, saturated aqueous solution of sodium chloride, successively. The organic layer was dried over magnesium sulfate and concentrated under reduced pressure. The concentrate was subjected to column chromatography (silica gel 650 g, hexane/ethyl acetate=30/1 to 10/1), and the desired fraction was concentrated under reduced pressure to give 1-tert-butoxycarbonyl-4-(4-fluorobenzylidene)piperidine (47.0 g). The obtained reaction mixture was distilled under reduced pressure (bp 115-120° C./1.5 mmHg)

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

Procedure: Prepared according to the same procedure as optically-enriched (4R,5R)-4-(5-bromopyridin-3-yl)-5-(3-methoxyphenyl)oxazolidin-2-one, starting with 6-bromopicolinaldehyde and diethyl 4-fluorobenzylphosphonate. 1H-NMR (CDCl3, 500 MHz) δ 7.65 (dd, J=7.9, 7.6, 1H), 7.51 (d, J=7.6, 1H), 7.46 (dd, J=8.9, 5.2, 2H), 7.41 (d, J=7.6, 1H), 7.13 (m, 3H), 5.61 (d, J=7.5, 1H), 4.90 (d, J=5.8, 1H). 13C-NMR (CDCl3, 126 MHz) δ 163.1 (d, J=249), 159.4 (d, J=55), 142.6, 139.8, 134.0, 128.3, 127.8, 127.7, 119.6, 116.2, 116.0, 83.1, 64.4. Prepared

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

Procedure: The title compound was prepared according the procedures described in Example 1, Part H and Example 1, Part I using the product obtained in Example 1, Part G (50 mg, 0.164 mmol) and diethyl 4-fluorobenzylphosphonate (40.5 mg, 0.164 mmol). The title compound was obtained as a solid (30 mg, 46%). 1H NMR (300 MHz, DMSO-d6): δ ppm 1.37 (s, 9H), 2.72 (t, J=6.6 Hz, 2H), 3.76 (s, 3H), 3.79 (t, =6.6 Hz, 2H), 7.21 (m, 4H), 7.30 (d, J=16.3 Hz, 1H), 7.53 (d, J=2.6 Hz, 1H), 7.73 (m, 2H), 10.35 (s, 1H). The title compound was prepared

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

Procedure: To a stirred suspension of 13.20 g of 60% sodium hydride (in oil) containing 1.65 g of 15-crown-5 ether in 650 ml of tetrahydrofuran were added dropwise a solution of 59.78 g of N-t-butoxycarbonylpiperidone and 81.25 g of diethyl 4-fluorobenzylphosphonate in 150 ml of tetrahydrofuran under ice-cooling over 20 minutes. After stirring at room temperature for a day, a saturated aqueous sodium bicarbonate solution was added cautiously, followed by extracting with ethyl acetate. The extract was washed with a saturated aqueous sodium bicarbonate solution and a saturated aqueous sodium chloride solution, successively, and dried over anhydrous sodium sulfate, followed by removal of the drying agent by filtration. The filtrate was concentrated under reduced pressure and purified by a flash column chromatography (silica gel: Wakogel C200 (manufactured by Wako Pure Chemicals), eluent; hexane-ethyl acetate =20:1) to give 55.23 g of N-t-butoxycarbonyl-4-(4-fluorobenzylidene)piperidine as an oil, which was then crystallized by allowing to stand at room temperature overnight. cooling over 20 minutes by extracting with ethyl acetate The extract was washed with a saturated aqueous sodium bicarbonate solution a saturated aqueous sodium chloride solution, successively, and dried over anhydrous sodium sulfate followed by removal of the drying agent by filtration The filtrate was concentrated under reduced pressure purified by a flash column chromatography (silica gel: Wakogel C200 (manufactured by Wako Pure Chemicals), eluent; hexane-ethyl acetate =20:1)

Conditions: temp:150.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4-fluorobenzyl bromide (100 g) and triethyl phosphite (120 ml) were mixed, and the mixture was stirred at 150° C. for 22 hours. The obtained reaction mixture was distilled under reduced pressure (bp 115-120° C./1.5 mmHg) to give diethyl 4-fluorobenzylphosphonate (125 g). To a solution of 4-fluorobenzylphosphonate (60.8 g), 15-Crown-5 (4 ml) in THF (400 ml) was added 60% sodium hydride in mineral oil (9.75 g) under ice cooling with stirring, and the mixture was stirred at the same temperature for 30 minutes. To the mixture was added dropwise a solution of 1-tert-butoxycarbonyl-4-piperidone (42.0 g) in THF (150 ml) under ice cooling, and the mixture was stirred at room temperature for 22 hours. After the addition of water under ice cooling, the mixture was extracted with ethyl acetate;, and the organic layer was washed with saturated aqueous solution of sodium hydrogencarbonate, saturated aqueous solution of sodium chloride, successively. The organic layer was dried over magnesium sulfate and concentrated under reduced pressure. The concentrate was subjected to column chromatography (silica gel 650 g, hexane/ethyl acetate=30/1 to 10/1), and the desired fraction was concentrated under reduced pressure to give 1-tert-butoxycarbonyl-4-(4-fluorobenzylidene)piperidine (47.0 g). The obtained reaction mixture was distilled under reduced pressure (bp 115-120° C./1.5 mmHg)

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

Procedure: A solution of 59.78 g of N-t-butoxycarbonylpiperidone and 81.25 g of diethyl 4-fluorobenzylphosphonate in 150 ml of tetrahydrofuran was added dropwise to a suspension of 13.20 g of 60% sodium hydride (in oil) containing 1.65 g of 15-crown-5 ether in 650 ml of tetrahydrofuran which was cooled in an ice bath over 20 minutes. After 1 day of stirring at room temperature, saturated aqueous sodium bicarbonate was carefully added to the reaction mixture which was subsequently extracted with ethyl acetate. The extract was washed with saturated aqueous sodium bicarbonate and saturated brine and dried over anhydrous sodium sulfate, the drying agent was removed by filtration, and then the resulting filtrate was concentrated under reduced pressure and purified by a flash column chromatography (silica gel: Wako Gel C200 (manufactured by Wako Pure Chemical Industries), eluant: hexane-ethyl acetate=20.1) to obtain 55.23 g of N-t-butoxycarbonyl-4-(4-fluorobenzylidene)piperidine. The thus obtained oily product was crystallized after its overnight standing at room temperature. was cooled in an ice bath over 20 minutes was subsequently extracted with ethyl acetate The extract was washed with saturated aqueous sodium bicarbonate and saturated brine dried over anhydrous sodium sulfate the drying agent was removed by filtration the resulting filtrate was concentrated under reduced pressure purified by a flash column chromatography (silica gel: Wako Gel C200 (manufactured by Wako Pure Chemical Industries), eluant: hexane-ethyl acetate=20.1)

Conditions: temp:150.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4-fluorobenzyl bromide (100 g) and triethyl phosphite (120 ml) were mixed, and the mixture was stirred at 150° C., for 22 hours. The obtained reaction mixture was distilled under reduced pressure (bp 115-120° C./1.5 mmHg) to give diethyl 4-fluorobenzylphosphonate (125 g). To a solution of 4-fluorobenzylphosphonate (60.8 g), 15-Crown-5 (4 ml) in THF (400 ml) was added 60% sodium hydride in mineral oil (9.75 g) under ice cooling with stirring, and the mixture was stirred at the same temperature for 30 minutes. To the mixture was added dropwise a solution of 1-tert-butoxycarbonyl-4-piperidone (42.0 g) in THF (150 ml) under ice cooling, and the mixture was stirred at room temperature for 22 hours. After the addition of water under ice cooling, the mixture was extracted with ethyl acetate, and the organic layer was washed with saturated aqueous solution of sodium hydrogencarbonate, saturated aqueous solution of sodium chloride, successively. The organic layer was dried over magnesium sulfate and concentrated under reduced pressure. The concentrate was subjected to column chromatography (silica gel 650 g, hexane/ethyl acetate=30/1 to 10/1), and the desired fraction was concentrated under reduced pressure to give 1-tert-butoxycarbonyl-4-(4-fluorobenzylidene)piperidine (47.0 g). The obtained reaction mixture was distilled under reduced pressure (bp 115-120° C./1.5 mmHg)