tert-Butanol → 5-(Boc-amino)-3-chloro-1-methyl-1H-pyrazole

Participants

Reaction Conditions

Reaction Steps

To a solution of 3-chloro-1-methyl-1H-pyrazole-5-carboxylic acid (2.0 g, 12.46 mmol) in THF (20 ml) was added Net3 (2.60 ml, 18.68 mmol) and diphenyl phosphoryl azide (5.14 g, 18.68 mmol) at 0° C. The mixture was stirred at it for 16 h and then, tert butanol (2.4 ml, 24.9 mmol) was added and the mixture heated at 70° C. for 9 h. Then, the solvents were removed under reduced pressure and the residue purified by column chromatography (eluent 60% hexane in EtOAc) to yield 2.13 g (74%) of the title compound. [1H-NMR (DMSO-d6, 360 MHz) δ 9.55 (br. s, 1H), 6.10 (d, 1H), 3.58 (s, 3H), 1.44 (s, 9H); HPLC-MS RtJ=0.93 min; [M+H]+=232.2, 234.2]

Provenance & Evidence