Diethyl Ether → {1-[(5-Cyclopropyl-[1,3,4]oxadiazol-2-yl)-hydroxy-methyl]-propyl}-carbamic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

A solution of 2-cyclopropyl-[1,3,4]oxadiazole (2.16 g, 19.6 mmol) in dry THF (100 mL) is cooled to −78° C. nBuLi (1.6M in hexanes, 12.3 mL, 19.6 mmol) is added dropwise. The reaction mixture is stirred at −78° C. for 40 min. MgBr2.OEt2 (5.0692 g, 19.6 mmol) is added. The reaction mixture is allowed to warm up to −45° C. and stirred at that temperature for 1.5 hr. A solution of (1-formyl-propyl)-carbamic acid tert-butyl ester (3.7 g, 19.6 mmol) in THF (40 mL) is added. The reaction mixture is allowed to warm up to −20° C. and stirred at that temperature for 3.5 hrs. The reaction mixture is quenched with a solution of saturated NH4Cl solution and extracted with ethyl acetate. Combined organic extracts is washed with saturated NaCl solution and dried over MgSO4. The solvent is evaporated under reduced pressure and the crude is purified by column chromatography eluting with ethyl acetate and heptane mixture to give {1-[(5-cyclopropyl-[1,3,4]oxadiazol-2-yl)-hydroxy-methyl]-propyl}-carbamic acid tert-butyl ester (2.83 g, 49%).

Provenance & Evidence