反应详情

4-(4-Chlorophenyl)pyrrole-2-carboxylic acid (0.6 g.) was hydrogenated over 200 mg. of 5% Pd/C in 50 ml. of ethanol for approximately 16 hours at 50 p.s.i. An additional 200 ml. of catalyst and 1 ml. of triethylamine was added and hydrogenation continued for 3 hours at 50 p.s.i. The catalyst was recovered by filtration, and the mother liquor concentrated to dryness to yield 4-phenylpyrrole-2-carboxylic acid [400 mg., m.p. 226°-228° C. (dec.), m/e 187]. For analysis, the product was recrystallized from acetone/hexane [240 mg., m.p. 227°-229° C. (dec.)].

1. filtrationThe catalyst was recovered by filtration
2. concentrationthe mother liquor concentrated to dryness