Triethylamine → tert-butyl 4-((3-iodo-1-isopropyl-1H-pyrazol-4-yl)methyl)-4-isocyanatopiperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of 1-(tert-butoxycarbonyl)-4-((3-iodo-1-isopropyl-1H-pyrazol-4-yl)methyl)piperidine-4-carboxylic acid (430 mg, 0.90 mmol) in toluene (10 mL) was added triethylamine (0.15 mL, 1.08 mmol) and diphenylphosphoryl azide (0.24 mL, 1.08 mmol). The mixture was heated at 120° C. for 3 hours, the volatiles were removed under reduced pressure and the resultant oil was purified by flash chromatography (7-60% ethyl acetate/heptanes, 25 g silica gel) to yield tert-butyl 4-((3-iodo-1-isopropyl-1H-pyrazol-4-yl)methyl)-4-isocyanatopiperidine-1-carboxylate (280 mg) as a clear oil. FT-IR (cm−1): 2253; 1H NMR (400 MHz, CDCl3, δ): 7.27 (s, 1H), 4.50 (m, 1H), 4.03 (br. s., 2H), 2.97 (br. s., 2H), 2.65 (s, 2H), 1.65 (m, 4H), 1.50 (s, 6H), 1.47 (s, 9H).

Provenance & Evidence