Réaction #156368

Équation de réaction

1-BOC-3-hydroxyazetidine

triethylamine

methanesulfonyl chloride

→

3-Methanesulfonyloxy-azetidine-1-carboxylic acid tert-butyl ester

Solvants

DCM

DCM

Conditions de réaction

Traitement

1. 1
   Lavagewashed with a solution of saturated NaHCO3 and brine
2. 2
   SéchageThe organic layer was dried over Na2SO4
3. 3
   Filtrationfiltered
4. 4
   Autrethe solvent was removed under reduced pressure

Mode opératoire

To a solution of 1-BOC-3-hydroxyazetidine (1.0 g, 5.77 mmol), 4-dimethylaminopyridine (7 mg, 0.058 mmol) and triethylamine (0.880 mL, 6.35 mmol) in DCM (15 mL) cooled at 0° C. was added dropwise methanesulfonyl chloride (0.45 mL, 5.77 mmol). The RM was stirred 18 h at rt, diluted with DCM, washed with a solution of saturated NaHCO3 and brine. The organic layer was dried over Na2SO4, filtered and the solvent was removed under reduced pressure. 3-Methanesulfonyloxy-azetidine-1-carboxylic acid tert-butyl ester obtained as an oil was used directly in the next step. To a solution of 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (1.4 g 5.57 mmol) in DMF (20 mL) stirred at 0° C. was added sodium hydride (55% in oil, 0.243 g, 5.57 mmol). After addition the mixture was stirred 1 h at rt, a solution of the above obtained 3-methanesulfonyloxy-azetidine-1-carboxylic acid tert-butyl ester (1.4 g, 5.57 mmol) in DMF (3 mL) was added. The RM was stirred 30 min at rt, and then 3 h at 95° C. After cooling at rt the mixture was poured in ice water and extracted with EtOAc. The combined organic phases were washed with a solution of saturated NaHCO3 and brine. The organic layer was dried over Na2SO4, filtered and the solvent was removed under reduced pressure. The residue was purified by flash chromatography (with heptane and EtOAc as eluants) to afford the title compound as an oil (tR 4.33 min (conditions 3), MH+=350.1)

Source