N-methoxy-N-methyloxane-4-carboxamide

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: Starting materials: (2R,6S)-4-(6-((tert-butyldiphenylsilyloxy)methyl)-2,3-difluorophenyl)-2,6-dimethylmorpholine (Intermediate 3) and N-methoxy-N-methyltetrahydro-2H-pyran-4-carboxamide.

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

Procedure: Starting materials: (2R,6S)-4-(6-((tert-butyldiphenylsilyloxy)methyl)-2,3-difluorophenyl)-2,6-dimethylmorpholine (Intermediate 3) and N-methoxy-N-methyltetrahydro-2H-pyran-4-carboxamide.

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

Procedure: A flask was charged with N-methoxy-N-methyltetrahydro-2H-pyran-4-carboxamide 2 (11.7 g, 67.5 mmol) and THF (350 mL). The resulting mixture was immersed in a cooling bath at −60° C., and methylmagnesium bromide (3.0 M in ether, 33.8 mL, 101.4 mmol) was added via syringe over ˜8 min. The temperature of the bath was allowed to rise to 0° C. over 6 h. At that time, the reaction was diluted with water and EtOAc and stirred vigorously for 10 min. The phases were separated, and the aqueous layer was extracted with EtOAc. The organic portions were combined, washed with brine, dried over MgSO4, filtered, and concentrated. The crude residue was subjected to column chromatography (120 g silica, 80 mL/min, 0% to 100% EtOAc/hexanes) to give 4-acetyltetrahydro-4H-pyran 3 (7.05 g, 55.0 mmol, 81%). 1H NMR (400 MHz, CDCl3) for 3: δ 3.95 (ddd, J=11.6, 4.4, 2.8 Hz, 2 H), 3.38 (dt, Jd=2.8 Hz, Jt=11.6 Hz, 2 H), 2.50 (m, 1 H), 2.12 (s, 3 H), 1.75 (m, 2 H), 1.65 (m, 2 H). LCMS for 3 (conditions D): tR=0.83 min, m/e=129.4 (M+H, base). The resulting mixture was immersed in a cooling bath at −60° C. The phases were separated the aqueous layer was extracted with EtOAc washed with brine dried over MgSO4 filtered concentrated

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

Procedure: To a solution of tetrahydro-2H-pyran-4-carboxylic acid 1 (4.0 g, 31 mmol) in DCM (65 mL) was added sequentially N,O-dimethylhydroxylamine hydrochloride (3.3 g, 34 mmol), 4-methylmorpholine (7.4 mL, 68 mmol), and N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (6.5 g, 34 mmol). The resulting mixture was stirred at RT for 18 h. At that time, the reaction was diluted with 1N HCl and EtOAc and stirred vigorously until both phases cleared. The phases were separated, and the aqueous layer was extracted with EtOAc. The organic portions were combined, washed with brine, dried over MgSO4, filtered, and concentrated. The crude residue was subjected to column chromatography (120 g silica, 80 ml/min, 0% to 100% EtOAc/hexanes) to give N-methoxy-N-methyltetrahydro-2H-pyran-4-carboxamide 2 (4.3 g, 24.8 mmol, 81%). LCMS for 2 (conditions D): tR=1.12 min, m/e=174.3 (M+H, base). stirred vigorously until both phases The phases were separated the aqueous layer was extracted with EtOAc washed with brine dried over MgSO4 filtered concentrated

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

Procedure: To a solution of tetrahydro-2H-pyran-4-carboxylic acid 1 (4.0 g, 31 mmol) in DCM (65 mL) was added sequentially N,O-dimethylhydroxylamine hydrochloride (3.3 g, 34 mmol), 4-methylmorpholine (7.4 mL, 68 mmol), and N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (6.5 g, 34 mmol). The resulting mixture was stirred at RT for 18 h. At that time, the reaction was diluted with 1N HCl and EtOAc and stirred vigorously until both phases cleared. The phases were separated, and the aqueous layer was extracted with EtOAc. The organic portions were combined, washed with brine, dried over MgSO4, filtered, and concentrated. The crude residue was subjected to column chromatography (120 g silica, 80 ml/min, 0% to 100% EtOAc/hexanes) to give N-methoxy-N-methyltetrahydro-2H-pyran-4-carboxamide 2 (4.3 g, 24.8 mmol, 81%). LCMS for 2 (conditions D): tR=1.12 min, m/e=174.3 (M+H, base). stirred vigorously until both phases The phases were separated the aqueous layer was extracted with EtOAc washed with brine dried over MgSO4 filtered concentrated

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

Procedure: A solution of n-BuLi (4.0 mL, 10 mmol, 2.5 M solution in hexane) was slowly added to a solution of 5-bromo-1,2-dimethyl-1H-imidazole (1.77 g, 10.2 mmol) in THF (70 mL) at −78° C. After addition, stirring was continued for an additional 30 minutes and N-methoxy-N-methyltetrahydro-2H-pyran-4-carboxamide (1.76 g, 10.1 mmol, Intermediate 1: step a, Procedure A) dissolved in THF (25 mL) was slowly added. An additional 6 mL of THF was used to complete the quantitative addition. The mixture was stirred at −78° C. for 5 minutes then warmed to room temperature and stirred for 1 hour. The solution was quenched with water and layers were separated. The aqueous layer was extracted with DCM and the combined organic extracts washed with brine, dried over MgSO4, filtered and evaporated in vacuo. The crude product was purified using flash column chromatography (0 to 6% MeOH/DCM) to provide the title compound. After addition was slowly added the quantitative addition The mixture was stirred at −78° C. for 5 minutes stirred for 1 hour The solution was quenched with water and layers were separated The aqueous layer was extracted with DCM the combined organic extracts washed with brine dried over MgSO4 filtered evaporated in vacuo The crude product was purified

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

Procedure: A clear colorless solution of 5-bromo-1-methyl-1H-imidazole (1.12 g, 6.93 mmol) in THF (10 mL) was placed in an ice bath and ethylmagnesium bromide (3.0 M in Et2O, 2.31 mL, 6.93 mmol) was added via syringe. The reaction mixture was stirred for 20 minutes at room temperature. N-Methoxy-N-methyltetrahydro-2H-pyran-4-carboxamide (1.0 g, 5.8 mmol, Intermediate 1: step a, Procedure A) was added neat by syringe (using 1 mL THF rinse to quantitate transfer), and the resulting white suspension was stirred at room temperature for 2 days. The mixture was diluted with saturated aqueous NH4Cl followed by water, then was extracted with EtOAc (3×). The organic phase was dried (Na2SO4), filtered, and concentrated to dryness. The crude product was purified by flash column chromatography two times (1-4% MeOH-DCM first column; 40-60% CH3CN-DCM second column) to provide the title compound as a white crystalline solid. (using 1 mL THF rinse to quantitate transfer) the resulting white suspension was stirred at room temperature for 2 days The mixture was diluted with saturated aqueous NH4Cl was extracted with EtOAc (3×) The organic phase was dried (Na2SO4) filtered concentrated to dryness The crude product was purified by flash column chromatography two times (1-4% MeOH-DCM first column; 40-60% CH3CN-DCM second column)

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

Procedure: A clear colorless solution of 5-bromo-1-methyl-1H-imidazole (1.12 g, 6.93 mmol) in THF (10 mL) was placed in an ice bath and ethylmagnesium bromide (3.0 M in Et2O, 2.31 mL, 6.93 mmol) was added via syringe. The reaction mixture was stirred for 20 minutes at room temperature. N-Methoxy-N-methyltetrahydro-2H-pyran-4-carboxamide (1.0 g, 5.8 mmol, Intermediate 1: step a, Procedure A) was added neat by syringe (using 1 mL THF rinse to quantitate transfer), and the resulting white suspension was stirred at room temperature for 2 days. The mixture was diluted with saturated aqueous NH4Cl followed by water, then was extracted with EtOAc (3×). The organic phase was dried (Na2SO4), filtered, and concentrated to dryness. The crude product was purified by flash column chromatography two times (1-4% MeOH-DCM first column; 40-60% CH3CN-DCM second column) to provide the title compound as a white crystalline solid. (using 1 mL THF rinse to quantitate transfer) the resulting white suspension was stirred at room temperature for 2 days The mixture was diluted with saturated aqueous NH4Cl was extracted with EtOAc (3×) The organic phase was dried (Na2SO4) filtered concentrated to dryness The crude product was purified by flash column chromatography two times (1-4% MeOH-DCM first column; 40-60% CH3CN-DCM second column)

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

Procedure: N,O-Dimethylhydroxylamine hydrochloride (1.23 g, 12.7 mmol) and N-methylmorpholine (3.80 mL, 34.5 mmol) were dissolved in DCM (20 mL) and a solution of oxane-4-carbonyl chloride (1.71 g, 11.5 mmol) in DCM (20 mL) was added drop-wise. The reaction mixture was stirred for 2 h, then diluted to 200 mL with DCM, washed with 1 M aq HCl (2×100 mL), 1M aq Na2CO3 (100 mL) and water (100 mL), dried (MgSO4) and concentrated in vacuo to give the crude title compound as a yellow oil (1.87 g, 94%). LCMS (ES+): 174.1 (M+H)+. washed with 1 M aq HCl (2×100 mL), 1M aq Na2CO3 (100 mL) and water (100 mL) dried (MgSO4) concentrated in vacuo