2-Methyl-2-butene → HCID 59598434, compound

Participants

Reaction Steps

The crude 1-methyl-3-oxo-2-phenyl-5-(pyridin-4-yl)-2,3-dihydro-1H-pyrazole-4-carbaldehyde was dissolved in t-BuOH (˜70 ml) and 2-methyl-2-butene (25 ml, 236 mmol) was added, followed by sodium chlorite (2.43 g, 27 mmol) in water (30 ml) with ˜5 ml water rinse. Then, potassium phosphate monobasic (10.35 g, 76 mmol) was added as a suspension in water (˜70 ml), and the reaction was stirred at room temperature. After 9 hours, the reaction was poured into water (400 ml) and the aqueous phase was then extracted with EtOAc, DCM, and 10:1 DCM/MeOH exhaustively until most of the product had been extracted. The organic extracts were combined, dried over sodium sulfate, filtered, and concentrated to give desired 1-methyl-3-oxo-2-phenyl-5-(pyridin-4-yl)-2,3-dihydro-1H-pyrazole-4-carboxylic acid (1.98 g, 6.7 mmol, 52% yield over two steps). MS (ESI pos. ion) m/z: 296 (MH+). Calc'd exact mass for C16H13N3O3: 295.

Provenance & Evidence