Ethanol → HCID 19710573, compound

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 5,8-dihydro-5-ethyl-2-methoxynaphthalene-1,4-dione (2.00 g, 9.16 mmol) in CHCl3 (100 mL, passed through silica gel prior to use), a solution of Cl2 in CCl4 (8.3 mL, ~1.1M) was added dropwise over a 5 min period. After addition, the reaction was allowed to stir an additional 30 min at 25° C. Analysis (NMR) indicated partial consumption of the starting material. An additional portion of the Cl2 solution (4 mL) was added. The reaction was allowed to stir at 25° C. for 1 hr. The analysis now indicated the absence of starting material. The solvent was removed in vacuo to give an orange syrup. The addition of 95% EtOH (10 mL) and steam bath warming prompted solidification. The solvent was removed in vacuo to given an orange solid. Crystallization from 95% EtOH (dissolved in boiling solvent (10 mL), hot filtered, allowed to cool to rt) yielded a yellow granular solid (1.37 g, 52%, pure by TLC (5% EtOAc/95% CHCl3), approximately a 2:1 mixture of diastereomers by NMR); mp 115°-118° C.; 1H NMR (CDCl3) δ1.03 (overlapping t, 3H), 1.90 (m, 2H), 2.93 (m, 1H), 3.27 (m, 2H), 3.82 (s, 3H), 4.40 (m, 2H), 5.90 and 5.92 (overlapping s, 1H); IR (KBr) 2970, 2938, 1675, 1652, 1633, 1609, 1226, 855 cm-1.

Provenance & Evidence