Sodium Hydroxide → 5-(p-Chlorobenzoyl)-3-hydroxycarbonyl-4-methoxy-1-methylpyrrole-2-acetic acid
Reaction equation
[Cl:1][C:2]1[CH:28]=[CH:27][C:5]([C:6]([C:8]2[N:12]([CH3:13])[C:11]([CH2:14][C:15]([O:17]CC)=[O:16])=[C:10]([C:20]([O:22]CC)=[O:21])[C:9]=2[O:25][CH3:26])=[O:7])=[CH:4][CH:3]=1.[OH-].[Na+]>C(O)C>[Cl:1][C:2]1[CH:3]=[CH:4][C:5]([C:6]([C:8]2[N:12]([CH3:13])[C:11]([CH2:14][C:15]([OH:17])=[O:16])=[C:10]([C:20]([OH:22])=[O:21])[C:9]=2[O:25][CH3:26])=[O:7])=[CH:27][CH:28]=1Participants
4
Procedure
Crude ethyl 5-(p-chlorobenzoyl)-3-ethoxycarbonyl-4-methoxy-1-methylpyrrole-2-acetate (505 mg) is suspended in 1 ml ethanol and heated to reflux. After all the solids dissolve, 5 ml of 2.5 N aqueous sodium hydroxide is added dropwise, causing an oil to separate at the end of the addition. However, the reaction mixture becomes homogeneous again after stirring vigorously at 100° for about 5 min. The reaction is then cooled, diluted with 5 ml water and acidified with 5.5 ml 2.5 N hydrochloric acid. The resulting precipitate is filtered, dried in vacuo to afford 478 mg of crude 5-(p-chlorobenzoyl)-3-hydroxycarbonyl-4-methoxy-1-methylpyrrole-2-acetic acid.