Imidazole → 4-Iodomethyl-2-(2-methylphenyl)benzoic acid, methyl ester

Participants

Reaction Steps

Triphenylphosphine (5.16 g), and imidazole (1.34 g) were dissolved in 3:1 ether:acetonitrile (80 mL), and the reaction was cooled to 0° C. Iodine (5.0 g) was added with vigorous stirring, and the reaction was warmed to ambient temperature. After 1 h, the reaction was recooled to 0° C. and 4-hydroxymethyl-2-(2-methylphenyl)benzoic acid, methyl ester (example 1178C, 4.6 g) was added as a solution in ether (20 mL). After 4 h at ambient temperature, the reaction was diluted with hexane/ether (1:1, 200 mL) and filtered. The filtrate was washed with a dilute solution of Na2SO3 until colorless, then with water (2×50 mL). The organic extracts were washed with brine (20 mL), dried (MgSO4), filtered and concentrated. The residue was purified by silica gel chromatography eluting with 10% EtOAc/hexane to give a light yellow oil (4.7 g) which slowly crystalizes in the freezer. 1H NMR (300 MHz, CDCl3) δ2.06 (s, 3H), 3.60 (s, 3H), 4.45 (ABq, JAB=9.7 Hz, ΔνAB=6.7 Hz, 2H), 7.03 (brd, J=6.6 Hz, 1H), 7.17-7.29 (m, 4H), 7.41 (dd, J=8.1, 1.6 Hz, 1H), 7.90 (d, J=8.1 Hz, 1H)). MS(CI/NH3) m/e: (M+NH4)+ 384.

Provenance & Evidence