Ethylparaben → Ethyl 4-hydroxy-3-iodobenzoate

Participants

Reaction Conditions

Reaction Steps

Charge a 10 L double jacketed reactor with a mechanical stirrer and a reflux condenser with 4-hydroxy benzoic acid ethyl ester (967 g, 8.81 mol) and acetic acid (5.8 L). Heat the mixture to 65° C. and add a solution of ICl (1010 g) in acetic acid (1 L) in ½ h. Stir the resulting mixture at 60-62° C. for 16 h. Cool the black solution to 20° C. and transfer on water (5 L) and ice (7.5 kg). Stir the resulting suspension over 1 h at 20° C., filter and wash the cake with water (2 L) and cyclohexane (6 L). Dry the solid under vacuum at 55° C. till constant weight to give 4-hydroxy-3-iodo-benzoic acid ethyl ester (1372.8 g, 4.70 mol). 11H NMR (250 MHz, CDCl3): 1.38 (t, J=7.1 Hz, 3H), 4.35 (quartet, J=7.1 Hz, 2H), 5.8 (s, 1 H), 7.01 (d, J=8.5 Hz, 1H), 7.95 (dd, J=8.5 Hz, 2.0 Hz, 1H), 8.37 (d, J=2 Hz, 1 H).

Provenance & Evidence