2,4,6-Trimethylphenyl isocyanate → 1-Mesityl-3-(1-methyl-2-pyrrolidylidene)urea

Participants

Reaction Steps

The hydrochloride salt of 2-imino-1-methylpyrrolidine (6.73 g.; 0.05 mole) is converted to free base (4.0 g.; 0.05 mole) by adding 10 ml. of 50% NaOH to an aqueous slurry (minimal amount of water) of the salt and benzene extraction. After drying over K2CO3, the benzene solution is stirred at room temperature and 8.06 g. (0.05 mole) of 2,4,6-trimethylphenylisocyanate [made according to the method of K. Inukai and Y. Maki, Kogyo Kagaku Zasshi, 70 (4), 491-4 (1967)] dissolved in anhydrous benzene is added. The reaction mixture is stirred at room temperature for 11/2 hours and then the solvent is evaporated in vacuo leaving an oily residue, which crystallizes on cooling. Recrystallization from acetone yields the pure product, 1-mesityl-3-(1-methyl-2-pyrrolidylidene)urea, m.p. = 121°-123° C.

Provenance & Evidence