Dimethylformamide → 9-Benzyl-1,2,3,9-tetrahydro-4H-carbazol-4-one

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Reaction Steps

Sodium hydride (60% in oil; 0.207 g, 5.18 mmol) is washed three times with hexane. DMF (3 mL) is added, followed by 36B added in portions. A moderate exotherm ensued; THF (3 mL) is added. After ten minutes benzyl bromide (1.047 g, 6.12 mmol) is added. After stirring for 4 h, an additional 0.1 g of benzyl bromide is added. The mixture is stirred overnight and then the solvents are removed; the residue is partitioned between CH2C2 and aq. sodium bicarbonate. The organic layers are dried over sodium sulfate. Chromatography on silica gel (150 mL) using CH3OH—CH2Cl2 (1/99) as eluent, followed by re-chromatography of mixed fractions using EtOAc-hexane (30/70), gave 1.023 g (79%) of the title compound; mp 157.0-157.5° C.; IR (drift) 2940, 1636, 1610, 1530, 1484, 1464, 1445, 1399, 1357, 1187, 1133, 749, 742, 731, 698 cm−1; 1H NMR (CDCl3) δ2.23, 2.60, 2.88, 5.34, 7.03, 7.2-7.3, 8.30. Anal. Calcd for C19H17NO: C, 82.88; H, 6.22; N, 5.09. Found: C, 82.51; H, 6.21; N, 5.13.

Provenance & Evidence