Methyl propiolate → 5-Butanoyl-6-methylpyridin-2(1H)-one

Participants

Reaction Steps

C-7. 5-(n-Butanoyl)-6-methyl-2(1H)-pyridinone--A mixture containing 22.2 g of 3-methyl-5-n-propylisoxazole [Kashima et al., Bull. Chem. Soc. Japan 46, 310-313 (1973)], 500 mg of platinum dioxide and 200 ml of ethanol was hydrogenated under catalytic hydrogenation conditions for ninety minutes, the catalyst was filtered off and the filtrate was concentrated on a rotary evaporator to yield 18.5 g of colorless residue which solidified on cooling. The residue containing 2-amino-2-hepten-4-one was dissolved in 50 ml of dimethylformamide and to the solution was added 14.8 g of methyl 2-propynoate. The resulting reaction solution was allowed to stand at ambient temperature for thirty minutes (exothermic) and then refluxed for three and one half hours. The dimethylformamide was removed on a rotary evaporator. The remaining dark brown liquid was heated in an oil bath at 195°-200° C. for four hours, cooled to room temperature, crystallized from isopropyl alcohol and dried at 80°-85° C. to produce, as pale yellow flakes, 9.4 g of 5-(n-butanoyl)-6-methyl-2(1H)-pyridinone, m.p. 167°-168° C.

Provenance & Evidence