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

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.

1. temperatureon cooling
2. customThe resulting reaction solution
3. waitto stand at ambient temperature for thirty minutes
4. temperature(exothermic) and then refluxed for three and one half hours
5. customThe dimethylformamide was removed on a rotary evaporator
6. temperatureThe remaining dark brown liquid was heated in an oil bath at 195°-200° C. for four hours
7. customcrystallized from isopropyl alcohol
8. customdried at 80°-85° C.

ORD record

ord-f1c94ed373dd4f559172fb79b6aca8f5

Source dataset

uspto-grants-1985_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04559347