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

HRID 1047596Notes

Reaction equation

[C:1]([O:5][C:6]([NH:8][C@@H:9]([C:11]([OH:13])=O)[CH3:10])=[O:7])([CH3:4])([CH3:3])[CH3:2].[C:14](=[N:17]O)([NH2:16])[CH3:15].C(Cl)CCl.C(OCC)(=O)C>O1CCOCC1.CN(C)C=O>[C:1]([O:5][C:6](=[O:7])[NH:8][C@@H:9]([C:11]1[O:13][N:17]=[C:14]([CH3:15])[N:16]=1)[CH3:10])([CH3:2])([CH3:3])[CH3:4]

Participants

Conditions

Temperature: 60 °C

Procedure

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 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 carbamate+H)+1).

Workup

temperatureAfter cooling to ambient temperature
washThe mixture was washed with aqueous saturated sodium bicarbonate (2×)
dry with materialThe combined organic extracts were dried over magnesium sulfate
filtrationfiltered
concentrationconcentrated
customThe residue was purified by silica gel chromatography (100% dichloromethane→90% dichloromethane/methanol)

Sources & evidence

ORD record: ord-6b95f81626ea42f2b213e53738c87513
Source dataset: uspto-grants-2013_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08569512B2

Reaction notes

Loading…