Phenolphthalein → Valine, N-[4-(trifluoromethyl)phenyl]-

Participants

Reaction Steps

Two grams of α-bromoisovaleric acid (0.011 mole) dissolved in 10 ml of methanol is titrated to the phenolphthalein end point at 0° with 2 N sodium hydroxide/methanol. The alcohol is then removed and 10 ml of dimethylformamide and p-trifluoromethylaniline (3.54 g, 0.022 mole) added. The reaction mixture is heated at 100° for 2 hours and left at room temperature about 18 hours. The reaction mixture is poured into 50 ml of 0.1 N sodium hydroxide, washed with ether and the aqueous phase adjusted to pH 4 with conc. HCl and then extracted with chloroform (3×). The extracts are combined and washed with brine, dried, concentrated in a rotoevaporator and solvent removed under vacuum at about 50° to yield N-(p-trifluoromethylphenyl)valine.

Provenance & Evidence