Benzyl chloroformate → 1,2,3,5-Tetrahydro-benzo[e][1,4]diazepine-4-carboxylic acid benzyl ester

HRID 1246949Notes

Reaction equation

[NH:1]1[C:7]2[CH:8]=[CH:9][CH:10]=[CH:11][C:6]=2[CH2:5][NH:4][CH2:3][CH2:2]1.CCN(C(C)C)C(C)C.Cl[C:22]([O:24][CH2:25][C:26]1[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=1)=[O:23]>C1COCC1>[NH:1]1[C:7]2[CH:8]=[CH:9][CH:10]=[CH:11][C:6]=2[CH2:5][N:4]([C:22]([O:24][CH2:25][C:26]2[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=2)=[O:23])[CH2:3][CH2:2]1

Participants

Conditions

Temperature: 0 °C

Procedure

2,3,4,5-Tetrahydro-1H benzo[e][1,4]diazepine (5 g, 33.7 mmol) was dissolved in THF (168.5 mL and cooled to 0° C. with an ice bath. Hunig's base (8.81 mL, 50.6 mmol) and benzyl chloroformate (5.30 mL, 37.1 mmol) was added dropwise with stirring. After 7 hours stirring, THF was removed, and water and ethyl ether were added to the flask. The reaction mixture was extracted with diethyl ether (4×), and the combined organic extracts were washed with aqueous sodium bicarbonate (1×) and brine (1×). The organic extracts were then dried with magnesium sulfate, filtered and concentrated to give a yellow oil. Further purification (25:75 ethyl acetate/hexane, then 30:70 ethyl acetate/hexane) yielded 7.9 g of desired product (83%).

Workup

stirringAfter 7 hours stirring
customTHF was removed
additionwater and ethyl ether were added to the flask
extractionThe reaction mixture was extracted with diethyl ether (4×)
washthe combined organic extracts were washed with aqueous sodium bicarbonate (1×) and brine (1×)
dry with materialThe organic extracts were then dried with magnesium sulfate
filtrationfiltered
concentrationconcentrated
customto give a yellow oil
customFurther purification (25:75 ethyl acetate/hexane

Sources & evidence

ORD record: ord-383d3fb2706f4377bab37f7395eed92c
Source dataset: uspto-grants-2006_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07129237B2

Reaction notes

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