Iodine → 1,3-Diethyl-4-iodo-5-methylpyrazole

Participants

Reaction Steps

A mixture of 13.2 g (95.7 mmol) of 1,3-diethyl-4-5-methylpyrazole (from Step C) and 1.50 g (3.7 mmol) of sorbitan monopalmitate in 200 mL of 2.5 N NaOH was treated with 44 g (0.17 mol) of iodine. Additional portions of sorbitan monopalmitate and iodine were added after 30 min and 60 min. The mixture was partitioned between 1 L of ether and 500 mL of water and the layers were separated. The organic layer was washed with 500 mL of 5% Na2S2O3, dried over MgSO4 and concentrated. Chromatography on a Biotage 75L using 9:1 heptane/EtOAc as the eluant afforded the title compound. 1H-NMR (400 MHz) δ 1.22 (t, J=7.6, 3H), 1.36 (t, J=7.2, 3H), 2.27 (s, 3H), 2.58 (q, J=7.6, 2H), 4.10 (q, J=7.2, 2H).

Provenance & Evidence