Methylamine → 1-Methyl-3-(2,2-dimethylpropionyl)-5-(3-trifluoromethylphenyl)-4(1H)-pyridinone

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Reaction Steps

A 3.6 g. portion of impure 6,6-dimethyl-1-dimethylamino-2-(3-trifluoromethylphenyl)-1-heptene-3,5-dione was dissolved in 17 ml. of N,N-dimethylformamide dimethyl acetal and stirred under reflux at about 100° overnight using a sub-surface nitrogen bubbler. The mixture was then evaporated under vacuum to obtain 3.5 g. of a dark oil, which was dissolved in 120 ml. of tetrahydrofuran and reacted with 15 ml. of 40% aqueous methylamine at ambient temperature for 1 hour. The mixture was then evaporated under vacuum, and the resulting oil was chromatographed on a 300 g. silica gel column with 2:3 ethyl acetate:dichloromethane as the eluting solvent. The product-containing fractions were combined and evaporated under vacuum, and the residue was triturated under hexane to obtain 0.6 g. of the desired product, m.p. 86°-88°, showing the following peaks on nmr analysis in DMSOd6 : δ7.6-8.2 (m, 6H, aromatic); 3.8 (s, 3H, N--CH3); 1.2 (s, 9 H, C(CH3)3).

Provenance & Evidence