Diisopropylamine → HCID 69450603, compound

Participants

Reaction Conditions

Reaction Steps

A solution of BuLi (13.3 mmol) in hexane (1.6 M, 8.3 mL) was added to a stirred solution of iPr2NH (1.87 mL, 13.3 mmol) in THF (15 mL) at 0° C. under N2. The resulting solution was stirred for 20 min and then cooled to −78° C. and N-methyl pyrazole (0.99 g, 12.1 mmol) was added. The mixture was stirred for 1 h at −78° C. and then a solution of ZnCl2 (1.8 g, 13.3 mmol) in THF (10 mL) was added and the reaction was allowed to warm to RT and stirred for a further 20 min. A solution of 1-(tert-butoxycarbonyl)-4-[(trifluoromethanesulfonyl)oxy]-1,2,3,6-tetrahydropyridine (Synthesis 1991, 11, 993–5) (150 mg, 0.53 mmol) in THF (5 mL) and Pd(PPh3)4 (347 mg, 5 mol %) were added and the reaction was heated at reflux for 3 h. The mixture was partitioned between EtOAc (75 mL) and NH4Cl solution (75 mL), separated and the organics were washed with H2O (75 mL) and brine (50 mL). After concentrating under reduced pressure, the residue was purified by column chromatography on silica eluting with 100% EtOAc to yield the pyrazole (1.30 g, 82%). 1H NMR (CDCl3, 360 MHz) δ 7.41 (1H, d, J=1.9 Hz), 6.13 (1H, d, J=1.9 Hz), 5.83 (1H, broad s), 4.10–4.00 (2H, m), 3.88 (3H, s), 3.62 (2H, t, J=5.7 Hz), 2.45–2.37 (2H, m), 1.49 (9H, s). MS (ES+) C14H21N3O2 requires: 263, found: 264 (M+H+, 100%).

Provenance & Evidence