反应详情

To a stirred solution of 50.0 g 1-(4-bromophenyl)-2,5-dimethylpyrrole (Meakins et al, J. Chem. Soc., Perkin Trans. I, 1984, 2801-2807) and tri-O-tolylphosphine (2.5 g) in triethylamine (100.0 ml), under a nitrogen atmosphere, is added decolorizing carbon (5.0 g) and palladium chloride (0.35 g). To this stirred slurry is added acrylic acid (20.0 g) followed by triethylamine (39.0 ml). The reaction mixture is refluxed for 4.5 hours, cooled to room temperature and diluted with water (700 ml). The pH of the reaction mixture is adjusted to ca. 2 by the slow addition of concentrated hydrochloric acid (63 ml). The solids are collected by filtration and the filter cake is washed with water until the pH is ca. 7 and then dried. The dried filter cake is suspended in boiling ethanol (350 ml), clarified, cooled to room temperature and diluted with water (450 ml) to induce crystallization. The slurry is cooled to -10° C. and the product collected by filtration. The filter cake is dried in vacuo at 45°. The dried solid is slurried in cold toluene, filtered and to dried to afford 3-[4-(2,5-dimethyl-1H-pyrrol-1-yl)phenyl)-2-propenoic acid, m.p. 184°-185°.

1. temperatureThe reaction mixture is refluxed for 4.5 hours
2. filtrationThe solids are collected by filtration
3. washthe filter cake is washed with water until the pH is ca. 7
4. customdried
5. filtrationThe dried filter cake
6. temperaturecooled to room temperature
7. additiondiluted with water (450 ml)
8. customcrystallization
9. temperatureThe slurry is cooled to -10° C.
10. filtrationthe product collected by filtration
11. customThe filter cake is dried in vacuo at 45°
12. filtrationfiltered
13. customto dried