Methyl iodide → 2,4-Dicarbethoxy-1,3-dimethylpyrrole

Reaction equation

[C:1]([C:6]1[NH:7][CH:8]=[C:9]([C:12]([O:14][CH2:15][CH3:16])=[O:13])[C:10]=1[CH3:11])([O:3][CH2:4][CH3:5])=[O:2].[C:17]([O-])([O-])=O.[K+].[K+].IC>CC(C)=O>[C:1]([C:6]1[N:7]([CH3:17])[CH:8]=[C:9]([C:12]([O:14][CH2:15][CH3:16])=[O:13])[C:10]=1[CH3:11])([O:3][CH2:4][CH3:5])=[O:2]

Participants

Procedure

A solution of 2,4-dicarbethoxy-3 methylpyrrole (25) (2.44 g, 10.9 mmol), K2CO3 (9.9 g), and iodomethane (55 ml) in 750 ml acetone was refluxed at 50° C. for 15 hours. The solution was concentrated in vacuo, partitioned between 450 ml of dichloromethane and 600 ml of water. The aqueous layer was extracted with CH2Cl2 (2×500 ml), dried (sodium sulfate), and concentrated in vacuo to yield a brown oil that solidified upon standing at room temperature for several minutes and was used without further purification. (2.37 g. 91% yield). TLC (benzene) Rf 0.3; 1H NMR (CD2Cl2) δ7.31 (s, 1H), 4.23 (m, 4H), 3.84 (s, 3H), 2.54 (2, 3H), 1.33 (m, 6H).