N-Iodosuccinimide → 3-Iodo-2,5-dimethyl-7-(pentan-3-yl)pyrazolo[1,5-a]pyrimidine

Participants

Reaction Steps

Dissolve 7-(1-ethyl-propyl)-2,5-dimethyl-pyrazolo[1,5-a]pyrimidine (2.14 g, 9.84 mmol) in anhydrous acetonitrile (25 mL) and add 6 portions (0.5 g each) of N-iodosuccinimide (3.0 g, 13.3 mmol) at 10 min intervals. Stir the reaction for 4 h. Strip off the acetonitrile and dilute the resulting oil with dichloromethane (100 mL). Wash the orange solution with saturated ammonium chloride solution (2×50 mL). Collect the organic phase, dry over anhydrous magnesium sulfate, filter, and concentrate under reduced pressure to yield a dark red oil. Purify using flash chromatography, eluting with 100% pentane/0% (20% ethyl acetate/pentane) to 0% pentane/100% (20% ethyl acetate/pentane) in a step gradient of 50% increments to give an orange oil (3.28 g, 97%). 1H NMR (400 MHz, CDCl3): 6.44 (s, 1H), 3.59 (m, 1H), 2.61 (s, 3H), 2.49 (s, 3H), 1.86-1.76 (m, 4H), 0.85 (t, J=7.5 Hz, 6H).

Provenance & Evidence