2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → HCID 66869528, compound

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Reaction Steps

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]+.

Provenance & Evidence