Formaldehyde → HCID 68453287, compound

Participants

Reaction Steps

To a suspension of 4-ethyl-3-nitrobenzoic acid tert-butyl ester (11e) (10 g, 40 mmol) and paraformaldehyde (1.8 g, 60 mmol) in DMSO (10 mL) was added in portions potassium tert-butoxide (590 mg, 5.8 mmol), during which the colour of the reaction mixture was changing from yellow to purple. After stirring for 1 hour at room temperature, the reaction mixture was suspended in CH2Cl2, adsorbed onto silica gel (15 g) in vacuo and purified by flash chromatography (100 g silica, column: 3.5×14 cm, solvent: hexane/EA 3:1). The product was obtained as a yellow oil in 94% yield (10.57 g, 38 mmol). Rf=0.34 (hexane/EtOAc 3:1). 1H NMR (250 MHz, CDCl3) δ 8.27 (d, 1H, arom. H(3)), 7.58 (dd, 1H, arom. H(5)), 7.53 (d, 1H, arom. H(6)), 3.76 (m, 2H, α-CH2), 3.50 (sextet, 1H, β-CH), 1.81 (t, 1H, OH), 1.57 (s, 9H, 3×CH3 COOtBu), 1.31 (d, 3H, CH3).

Provenance & Evidence