Acetic Anhydride → 4-Ethoxy-3-(4-pyridyl)-3-buten-2-one
Reaction equation
[CH3:1][C:2]([CH2:4][C:5]1[CH:10]=[CH:9][N:8]=[CH:7][CH:6]=1)=[O:3].[CH:11](OCC)(OCC)[O:12][CH2:13][CH3:14].C(OC(=O)C)(=O)C>C(O)(=O)C>[CH3:1][C:2]([C:4]([C:5]1[CH:10]=[CH:9][N:8]=[CH:7][CH:6]=1)=[CH:11][O:12][CH2:13][CH3:14])=[O:3]Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Procedure
One aspect of the invention resides in the process which comprises reacting pyridinylmethyl lower-alkyl ketone of the formula ##STR1## (I) with tri-(lower-alkyl) orthoformate, acetic anhydride and acetic acid to produce 2-(lower-alkoxy)-1-(pyridinyl)-ethenyl lower-alkyl ketone of formula II, ##STR2## and reacting said ketone (II) with malononitrile in a lower-alkanol to produce 1,2-dihydro-6-R-2-oxo-5-PY-nicotinonitrile of formula III, ##STR3## where R and R' are each lower-alkyl and PY is 4- or 3-pyridinyl or 4- or 3-pyridinyl having one or two lower-alkyl substituents. In a preferred embodiment 4(or 3)-pyridinylmethyl methyl(or ethyl) ketone is first reacted with triethyl or trimethyl orthoformate, acetic anhydride and acetic acid to produce 2-ethoxy(or methoxy)-1-(4- or 3-pyridinyl)ethenyl methyl(or ethyl) ketone and then said ketone is reacted with malononitrile in ethanol to produce 1,2-dihydro-6-methyl(or ethyl)-2-oxo-5-[4(or 3)-pyridinyl]nicotinonitrile. In a particularly preferred embodiment 4-pyridinylmethyl methyl ketone is first reacted with triethyl orthoformate, acetic anhydride and acetic acid to produce 2-ethoxy-1-(4-pyridinyl)ethenyl methyl ketone and then said ketone is refluxed with malononitrile in ethanol to produce 1,2-dihydro-6-methyl-2-oxo-5-(4-pyridinyl)nicotinonitrile.
Sources & evidence
- ORD record
- ord-7ca8f9382fc54b9fac8de13c9ab9eccf
- Source dataset
- uspto-grants-1983_11
- Patent number
- US04413127
Reaction notes
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