1-Bromopentane → 1-t-butoxycarbonyl-4-(1-pentyl-1H-benzimidazol-2-yl)[1,4]diazepane

HRID 1584480Notes

Reaction equation

[C:1]([O:5][C:6]([N:8]1[CH2:14][CH2:13][CH2:12][N:11]([C:15]2[NH:19][C:18]3[CH:20]=[CH:21][CH:22]=[CH:23][C:17]=3[N:16]=2)[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].[H-].[Na+].[CH2:26](Br)[CH2:27][CH2:28][CH2:29][CH3:30]>CN(C)C=O.ClCCl>[C:1]([O:5][C:6]([N:8]1[CH2:14][CH2:13][CH2:12][N:11]([C:15]2[N:16]([CH2:26][CH2:27][CH2:28][CH2:29][CH3:30])[C:17]3[CH:23]=[CH:22][CH:21]=[CH:20][C:18]=3[N:19]=2)[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:2])[CH3:3]

Participants

Conditions

Temperature: 80 °C

Procedure

Combine 1-t-butoxycarbonyl-4-(1H-benzimidazol-2-yl)[1,4]diazepane (0.8 g, 2.5 mmol) in dimethylformamide (10 mL). Add sodium hydride (0.13 g, 60% in oil, 3.25 mmol) portionwise. After about 30 minutes, when the gas evolution ceases, add pentyl bromide (0.34 mL, 2.74 mmol). Heat to 80° C. After 18 hours, cool the reaction mixture and dilute with dichloromethane (150 mL) and extract with brine. Dry the organic layer over MgSO4, filter, and evaporate in vacuo to give 1-t-butoxycarbonyl-4-(1-pentyl-1H-benzimidazol-2-yl)[1,4]diazepane: Rf =0.87 (silica gel, 5% methanol/dichloromethane/0.05% concentrated aqueous ammonia). Combine 1-t-butoxycarbonyl-4-(1-pentyl-1H-benzimidazol-2-yl)[1,4]diazepane (0.7 g, 1.8 mmol) and ethanol (5 mL). Add aqueous hydriodic acid (5 mL, 57%). Heat to reflux. After 1 hour, cool to ambient temperature and dilute with diethyl ether (250 mL) and stir to give a solid. Collect the solid by filtration, rinse with diethyl ether, and dry to give the title compound.

Workup

waitAfter 18 hours
temperaturecool the reaction mixture
extractionextract with brine
dry with materialDry the organic layer over MgSO4
filtrationfilter
customevaporate in vacuo

Sources & evidence

ORD record: ord-e00826e9e9434c378d1f9ed5ebcae831
Source dataset: uspto-grants-1999_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05932571

Reaction notes

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