反应详情

2,4-Dimethyl-5-carbethoxy-pyrrole (0.83 g), acetic acid (10 ml), hydriodic acid (10 ml) and paraformaldehyde (0.60 g) were stirred 3 hours at 25° C. under nitrogen. Hypophosphorous acid (50%, about 1 ml) was added, dropwise to decolourize the solution. The cooled solution (0° C.) was made basic with ammonium hydroxide and the product was extracted with ether (2 × 20 ml). The extract was dried over magnesium sulfate, filtered, and the ether removed in a rotating evaporator at 20° C. Recrystallization of the residue from benzene gave the product, 0.58 g (64%), m.p. 125°-126° C. (lit3 m.p. 126° C.).

1. customThe cooled solution (0° C.)
2. extractionthe product was extracted with ether (2 × 20 ml)
3. dry with materialThe extract was dried over magnesium sulfate
4. filtrationfiltered
5. customthe ether removed in a rotating evaporator at 20° C
6. customRecrystallization of the residue from benzene
7. customgave the product, 0.58 g (64%), m.p. 125°-126° C. (lit3 m.p. 126° C.)