Triphenylphosphine → 2-Chlorobenzene-1-sulfonic acid

Participants

Reaction Conditions

Reaction Steps

Diethyl azodicarboxylate (524 mg, 3.0 mmol) was added to a solution of 2-chlorobenzenesulfonic acid 3-hydroxy-5-methylphenyl ester (900 mg, 3.0 mmol), as prepared in step (c) of the Example 1,4-cyanobenzyl alcohol (400 mg, 3.0 mmol; Yoon et al., J. Org. Chem. 38:2786-2792 (1973)), and triphenylphosphine (790 mg, 3.0 mmol) in tetrahydrofuran (20 miL) at 0° C. The mixture was stirred at 0° C. for 2 h and at room temperature for 3 h. The reaction mixture was quenched with water (50 mL) and extracted with ethyl acetate (3×50 mL). The organic phase was washed sequentially with saturated NaHCO3 (2×50 mL) and brine (2×50 mL), and dried over Na2SO4. The solvent was removed in vacuo and the residue was purified by flash column chromatography (2:1 ethyl acetate:hexane) to give the title compound as a white solid (0.95 g, 76%). 1H-NMR (300 MHz, CDCl3) δ 2.26 (s, 3H), 5.03 (s, 1 H), 6.57 (t, 1 H, J=2.2 Hz), 6.59 (s, 1H), 6.67 (s, 1H), 7.38 (t, 1 H, J=5.8 Hz), 7.49 (d, 2H, J=4.2 Hz), 7.60 (m, 2H), 7.67 (d, 2H, J=3.5 Hz) and 7.96 (d, 1H, J=3.6 Hz).

Provenance & Evidence