Triethylamine → tert-Butyl 6-(5-bromopentanamido)-1,4-oxazepane-4-carboxylate

Reaction equation

[NH2:1][CH:2]1[CH2:8][O:7][CH2:6][CH2:5][N:4]([C:9]([O:11][C:12]([CH3:15])([CH3:14])[CH3:13])=[O:10])[CH2:3]1.CCN(CC)CC.[Br:23][CH2:24][CH2:25][CH2:26][CH2:27][C:28](Cl)=[O:29]>>[Br:23][CH2:24][CH2:25][CH2:26][CH2:27][C:28]([NH:1][CH:2]1[CH2:8][O:7][CH2:6][CH2:5][N:4]([C:9]([O:11][C:12]([CH3:15])([CH3:14])[CH3:13])=[O:10])[CH2:3]1)=[O:29]

Participants

Reactant 3

HCID 8471Triethylamine

HCID 5211735-Bromovaleryl chloride

HCID 44119210tert-Butyl 6-amino-1,4-oxazepane-4-carboxylate

Product 1

HCID 67972701tert-Butyl 6-(5-bromopentanamido)-1,4-oxazepane-4-carboxylate

Procedure

To an ice bath stirring solution of tert-butyl 6-amino-1,4-oxazepane-4-carboxylate 38.4 (1.01 g, 4.67 mmol) and Et3N (1.95 mL, 14.0 mmol) was added 5-bromo-pentanoyl chloride (0.62 mL, 4.7 mmol). The ice bath was removed and the solution was stirring for 1 h and then diluted with water and extracted with DCM. The organic phase was washed with diluted citric acid, water, sat. NaHCO3, dried (MgSO4), filtered and concentrated in vacuo to afford an oil which was purification by flash column chromatography (gradient EtOAc/hexanes). LCMS m/z 324.1 & 325.1 [M-tBu]+.