1,2-Dichloroethane → Tert-butyl (R)-(1-(3-methyl-1,2,4-oxadiazol-5-YL)ethyl)carbamate

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Reaction Conditions

Reaction Steps

To a solution of N-(tert-butoxycarbonyl)-D-alanine (20 g, 106 mmol), acetamide oxime (17.3 g, 234 mmol) in 120 mL of 1,4-dioxane and 30 mL of N,N-dimethylformamide were added EDC (44.8 g, 234 mmol). The mixture was heated at 60° C. for 4 h then at 100° C. for 16 h. After cooling to ambient temperature, 300 mL of ethyl acetate was added. The mixture was washed with aqueous saturated sodium bicarbonate (2×). The combined organic extracts were dried over magnesium sulfate, filtered and concentrated. The residue was purified by silica gel chromatography (100% dichloromethane→90% dichloromethane/methanol) to give pure tert-butyl[(1R)-1-(3-methyl-1,2,4-oxadiazol-5-yl)ethyl]carbamate (6.0 g). MS 172.1 ((M-t-butyl+H)+1).

Provenance & Evidence