Methyl iodide → 2-Methyl-2,3,5,6,7,8-hexahydro-3,8-isoquinolinedione
Reaction equation
[CH:1]1[NH:2][C:3](=[O:12])[CH:4]=[C:5]2[C:10]=1[C:9](=[O:11])[CH2:8][CH2:7][CH2:6]2.[CH3:13]I>C1C=CC=CC=1.C(=O)([O-])[O-].[Ag+2]>[CH3:13][N:2]1[C:3](=[O:12])[CH:4]=[C:5]2[C:10]([C:9](=[O:11])[CH2:8][CH2:7][CH2:6]2)=[CH:1]1Participants
Procedure
The novel compounds of the present invention originate from a novel process which utilizes dihydroresorcinol as the starting material. That substance thus is allowed to react with a chlorinating reagent such as phosphorus trichloride to afford 3-chloro-2-cyclohexen-1-one. Reaction with cycnoacetamide and sodium hydride results in α-cyano-3-oxo-1-cyclohexen-1-acetamide, which is contacted with a dialkylformamide acetal, for example dimethylformamide diethyl acetal or dimethylformamide dineopentyl acetal, to produce 2,3,5,6,7,8-hexahydro-3,8-dioxo-4-isoquinolinecarbonitrile. Elimination of the cyano group is effected by heating with hydrobromic acid, thus affording 2,3,5,6,7,8-hexahydro-3,8-isoquinolinedione. Heating with an alkyl or cycloalkyl halide produces the corresponding 6-alkoxy and 6-cycloalkoxy 7-aza-1-tetralones together with the N-alkylated or N-cycloalkylated derivatives. Typically, 2,3,5,6,7,8-hexahydro-3,8-isoquinolinedione is heated in benzene at the reflux temperature with methyl iodide and silver carbonate to yield 7-aza-6-methoxy-1-tetralone together with 2-methyl-2,3,5,6,7,8-hexahydro-3,8-isoquinolinedione.
Sources & evidence
- ORD record
- ord-08802d88aac7411c97fa955fc0e69509
- Source dataset
- uspto-grants-1977_03
- Patent number
- US04012391
Reaction notes
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