Yield:869663-56-9 99%

Reaction Conditions:

with acetic acid in tetrahydrofuran;ethanol; for 16 h;Heating / reflux;

Steps:

6

A mixture of 4,4-dimethyl-3-oxo-pentanenitrile (4.52 g, 36.15 mmol), 4- hydrazinobenzoic acid (5.00 g, 32.86 mmol), and acetic acid (2 mL) in EtOH/THF (1:1) was refluxed for 16 h. After cooling, the solvent was concentrated under reduced pressure, and the crude was re-dissolved in EtOAc. The organic layer was washed successively with saturated aqueous solution of Na₂Cθ₃ and brine, dried (MgSO₄), filtered, and concentrated under reduced pressure to half its volume. The resulting precipitate was filtered, and the solids were washed with cold EtOAc and dried under high vacuum to afford the title compound as a white solid (8.4 g, 99%). ¹H-NMR (DMSO-cfe) δ 12.91 (s, 1 H), 7.99 (d, J = 6.0 Hz, 2H), 7.75 (d, J = 9.0 Hz, 2H), 5.42 (s, 1 H), 5.39 (s, 2H)₁ 1.21 (s, 9H); LC-MS m/z [M+H]⁺ = 260, RT = 1.83 min.

References:

WO2007/64872,2007,A2 Location in patent:Page/Page column 75-76