tert-Butanol → HCID 58563674, compound

Participants

Reaction Steps

To a solution of 4-oxo-4,5,6,7-tetrahydro-pyrazolo[1,5-a]pyridine-2-carboxylic acid (2.56 g, 14.2 mmol, prepared according to EP1241170) in 160 mL dry toluene is added triethylamine (2.38 mL, 17.1 mmol) and diphenylphosphoryl azide (3.68 mL, 17.1 mmol) and the reaction mixture is stirred overnight at RT. Then tert-butanol (26.7 mL, 74.1 mmol) is added and the reaction is heated to 120° C. for 5 h. The solvents are removed under reduced pressure and the residue is purified by flash column chromatography (silica gel, 0-70% ethyl acetate in cyclohexane). Yield: 2.32 g. HPLC-MS: Rt=1.55 min, (M+H-56)+=196. 1H NMR (DMSO-d6): δ 9.8 (s, 1H), 6.7 (s, 1H), 4.2 (t, 2H), 2.6 (t, 2H), 2.3 (quint, 2H), 1.4 (s, 9H).

Provenance & Evidence