Iodoethane → 1-ethyl-2-phenyl-2,5-dihydro-4H-pyrazolo[3,4-c]quinolin-4-one

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Reaction Conditions

Reaction Steps

Under a nitrogen atmosphere, a mixture of 2-phenyl-2,5-dihydro-4H-pyrazolo[3,4-c]quinoline-one (3.0 g, 11.5 mmol), N,N,N′-tetramethylethylenediamine (7.7 mL), and tetrahydrofuran (128 mL) was chilled to 0° C. A solution of n-butyllithium in hexanes (12.0 mL of 2.86 M) was added dropwise. After the addition was complete the reaction mixture was stirred for 5 minutes at 0° C. and then cooled to −78° C. To the cooled solution was added iodoethane (5.3 mL, 34 mmol). The reaction mixture was warmed to ambient temperature and stirred for 30 minutes before quenching with saturated aqueous ammonium chloride. The layers were separated and the organic layer was concentrated under reduced pressure to afford a yellow oil. The yellow oil was stirred in acetonitrile and filtered to provide material that was recrystallized from methanol to provide 100 mg of 1-ethyl-2-phenyl-2,5-dihydro-4H-pyrazolo[3,4-c]quinolin-4-one as colorless needles., mp 331-334° C. MS (APCI) m/z 290 (M+H)+; Anal. calcd for C18H15N3O: C, 74.72; H, 5.23; N, 14.52. Found: C, 74.51; H, 4.96; N, 14.62.

Provenance & Evidence