Benzaldehyde → HCID 11709006, compound

Participants

Reaction Conditions

Reaction Steps

A 25 mL round-bottom flask was charged with 3 (316 mg, 2.00 mmol), NMP (10 mL), benzaldehyde, (202 μL, 2.00 mmol), and a magnetic stirring bar. The flask was fitted with a Hickman still, placed in an oil bath heated to 120° C., and stirred for 1 h. Then FeCl3.6H2O (27 mg, 0.10 mmol) was added to the reaction vessel and oxygen was bubbled through the mixture as it was heated and stirred for an additional 20 h. The reaction mixture was then removed from heat and added to ethyl acetate. The ethyl acetate solution was washed three times with water, then washed with brine, dried over Na2SO4, filtered, and concentrated to dryness. The residue (458 mg, 1.88 mmol) was dissolved in NMP (2 mL) and heated to 80° C. Then DBU (280 μL, 1.88 mmol) was added and the mixture was stirred for 2 min, and iodopropane (183 μL, 1.88 mmol) was added. After 20 min, the mixture was treated with a second round of DBU and iodopropane, and after an additional 20 min, a third round of reagents was added. After a final 20 min of heating, the mixture was transferred to ethyl acetate and washed three times with water, followed by brine. After drying the organic layer over Na2SO4, the mixture was filtered, concentrated to dryness, and chromatographed (silica, CH2Cl2, 3% ethyl acetate, 1% isopropanol), yielding an off-white solid (253 mg, 44%): mp 183-185° C.; 1H NMR (CDCl3) δ 0.90 (t, J=7.6 Hz, 2H), 1.81-1.92 (m, 2H), 4.29 (t, J=7.6 Hz, 2H), 7.56-7.62 (m, 3H), 7.70-7.73 (m, 2H), 7.89 (s, 1H), 8.20 (s, 1H); 13C NMR (CDCl3) δ 11.4, 23.5, 47.3, 108.7, 109.0, 116.7, 116.8, 116.9, 126.6, 128.8, 129.5, 129.5, 131.4, 137.8, 145.4, 159.5; FAB-MS obsd 287.1302, calcd 287.1297 [(M+H)+; M=C18H14N4].

Provenance & Evidence