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 compounds of the present invention are prepared from a novel process which utilizes dihydroresorcinol as the starting material. Dihydroresorcinol is allowed to react with a chlorinating reagent such as phosphorous trichloride to afford 3-chloro-2-cyclohexen-1-one. Reaction with cyanoacetamide and sodium hydride results in α-cyano-3-oxo-1-cyclohexen-1-acetamide, which is then contacted with a dialkylformamide acetal, for example, dimethylformamide diethylacetal or dimethylformamide dineopentyl acetal, or trialkylorthoformate, for example triethylorthoformate, 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 halide produces the corresponding 6-alkoxy-7-aza-1-tetralone together with the N-alkylated derivative. 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-6bed225b38fa40948fa52510e9d81295
- Source dataset
- uspto-grants-1977_10
- Patent number
- US04053476
Reaction notes
Loading…