Dimethylformamide dimethyl acetal → (2E)-1-(1,3-diethyl-1H-indazol-6-yl)-3-(dimethylamino)prop-2-en-1-one

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Reaction Conditions

Reaction Steps

1,1-dimethoxy-N,N-dimethylmethanamine (0.891 g, 0.0075 mol) was added to a solution of 1-(1,3-Diethyl-1H-indazol-6-yl)-ethanone (0.187 mg, 8.64 mmol) in N,N-dimethylformamide (8 mL), and the resulting mixture was shaken at 120° C. for 16 hours. 1,1-dimethoxy-N,N-dimethylmethanamine (0.618 g, 0.0052 mol) was added, and the reaction was refluxed at 140° C. for a further 16 hours. The solvent was removed in vacuo, and the residue extracted with ethyl acetate (30 mL) and water (10 mL). The aqueous layer was re-extracted with ethyl acetate (30 mL). The organic layers were combined, dried, filtered and concentrated. The resulting crude product was purified by silica-gel chromatography, using an eluent gradient of 0.25-0.5% methanol in dichloromethane (mobile phase contained 0.5% ammonium hydroxide solution) to afford 35 mg of (2E)-1-(1,3-diethyl-1H-indazol-6-yl)-3-(dimethylamino)prop-2-en-1-one.

Provenance & Evidence