2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → HCID 66869528, compound
Reaction equation
ClC1CCC2C(=CC(OC)=CC=2)C1.C(OC(=O)C)C.[CH2:20]([O:22][C:23](=[O:38])[CH2:24][C:25]1[C:34]2[C:29](=[CH:30][CH:31]=[C:32]([O:35][CH3:36])[CH:33]=2)[CH2:28][CH2:27][C:26]=1[Cl:37])[CH3:21].ClC1C(=O)C(C#N)=C(C#N)C(=O)C=1Cl>O1CCOCC1.CO>[CH2:20]([O:22][C:23](=[O:38])[CH2:24][C:25]1[C:34]2[C:29](=[CH:30][CH:31]=[C:32]([O:35][CH3:36])[CH:33]=2)[CH:28]=[CH:27][C:26]=1[Cl:37])[CH3:21]Participants
Procedure
A mixture of [2-Chloro-7-methoxy-3,4-dihydro-2H-naphthalen-(1 E/Z)-ylidene]-acetic acid ethyl ester and of (2-Chloro-7-methoxy-3,4-dihydro-naphthalen-1-yl)-acetic acid ethyl ester (26.82 g, 95.52 mmol) is dissolved under an atmosphere of argon in dioxane (280 ml). 2,3-Dichloro-5,6-dicyano-p-benzoquinone (DDQ, 47.70 g, 210.16 mmol) is added, and the reaction mixture is refluxed for 2 h. TLC analysis indicates complete conversion of starting material. After cooling to RT, addition of MeOH renders the reaction mixture homogeneous. Silica gel (250 g) is added, and the solvent is removed by rotary evaporation. Purification by FCC (hexane/EtOAc 9:1) yields the title compound. 1H NMR (CDCl3, 400 MHz): δ 1.24 (t, J=8.8 Hz, 3H), 3.95 (s, 3H), 4.19 (q, J=8.8 Hz, 2H), 4.28 (s, 2H), 7.16-7.19 (m, 1H), 7.22 (s, 1H), 7.38 (d, J=10 Hz, 1H), 7.68 (d, J=10 Hz, 1H), 7.75 (d, J=10 Hz, 1H). ES+-MS: 279.2, 281.2 [M+H]+.
Workup
- temperaturethe reaction mixture is refluxed for 2 h
- additionSilica gel (250 g) is added
- customthe solvent is removed by rotary evaporation
- customPurification by FCC (hexane/EtOAc 9:1)
Sources & evidence
- ORD record
- ord-05850b90fe9b455b8754428efff80133
- Source dataset
- uspto-grants-2010_08
- Patent number
- US07781438B2
Reaction notes
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