Formaldehyde → HCID 10149289, compound

Participants

Reaction Conditions

Reaction Steps

BF3.OEt2 (2.2 ml, 17.5 mmol) was dropped to a mixture of benzodiazepine (0.74 g, 5 mmol), cyclopentene (3.6 ml, 40.0 mmol), paraformaldehyde (165 mg, 5.5 mmol) in acetonitrile (20 ml) at room temperature. The mixture was heated at 45° C. (oil bath) for 5 h. It was concentrated in vacuo. The residue was taken up with EtOAc (150 ml) and washed first with a mixture of aqueous Na2CO3 and NaOH (200 ml), and then with brine (200 ml). The organic layer was dried and added HCl (1 N in diethyl ether, 10 ml) and the resultant precipitates were collected by filtration. The mixture was purified by flash chromatography on silica gel (5-15% MeOH in CH2Cl2) to afford E (0.70 g, 53% yield.)

Provenance & Evidence