Acetic Acid → 4,5,6-Triethoxy-7-nitrophthalide

Reaction equation

C(O)(=O)C.[CH2:5]([O:7][C:8]1[C:17]([O:18][CH2:19][CH3:20])=[C:16]([O:21][CH2:22][CH3:23])[CH:15]=[C:14]2[C:9]=1[CH2:10][O:11][C:12]2=[O:13])[CH3:6].[N+:24]([O-])([OH:26])=[O:25]>O>[CH2:5]([O:7][C:8]1[C:17]([O:18][CH2:19][CH3:20])=[C:16]([O:21][CH2:22][CH3:23])[C:15]([N+:24]([O-:26])=[O:25])=[C:14]2[C:9]=1[CH2:10][O:11][C:12]2=[O:13])[CH3:6]

Participants

Procedure

Glacial acetic acid (14 ml) was added to 5.32 g (0.02 mole) of 4,5,6-triethoxyphthalide. Into the reaction mixture on a water bath at 30-35° C., 14 ml of fuming nitric acid, d=1.52, was gradually added dropwise over a time period of 9 hours. After completion of the addition, the reaction mixture was allowed to stand overnight at room temperature and thereafter 80 ml of water was added to deposit crystals. The crystals were filtered out, washed thoroughly with water and dried. There was obtained 2.20 g of 4,5,6-triethoxy-7-nitrophthalide having a melting point of 82.5-84.5° C. with a yield of 35%.