4-Nitrobenzaldehyde → 5-Nitro-2-[2-(4-nitro-phenyl)-vinyl]-benzenesulfonic Acid 2,2-Dimethylpropyl Ester

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Reaction Steps

2-(Diethoxyphosphorylmethyl)-5-nitro-benzenesulfonic acid, 2,2-dimethylpropyl ester Example 55, 1.15 g, 2.72 mmol) was dissolved in 55 mL of anhydrous tetrahydrofuran. Sodium hydride (0.12 g, 2.99 mmol) was added in one portion and the reaction mixture was stirred for twenty minutes. The solution turned a deep red color. After attaching a reflux condenser, 4-nitrobenzaldehyde (0.821 g, 5.43 mmol) was added and the mixture was heated to reflux in an oil bath. After six hours the solution was cooled to room temperature, diluted with ethyl acetate (300 mL), washed with brine (2×), washed with conc. sodium bisulfite (2×), and the organic layer was dried (MgSO4). After concentration on a rotovap the crude material was purified by a gradient flash column using 30 to 60% ethyl acetate in hexanes as the eluant to afford 1.13 g of the title compound as a yellow solid (91%): 1HNMR (CDCl3) δ8.91 (d, J=2 Hz, 1H), 8.51 (dd, J=9 Hz, 2 Hz, 1H), 8.29 (d, J=9 Hz, 2H), 8.09 (d, J=16 Hz, 1H), 8.06 (d, J=9Hz, 1H), 7.74 (d, J=9Hz, 2H), 7.31 (d, J=16 Hz, 1H), 3.75 (s, 2H), 0.88 (s, 9H); MS (ES-NEG): [M−H]− 419; Anal. Calc. for C19H20N2O7S: C, 54.28; H, 4.79; N, 6.66. Found: C, 54.13; H, 4.68; N, 6.54.

Provenance & Evidence