Ammonia → HCID 54403606, compound

Participants

Reaction Steps

A solution of 6.5 g (0.021 mole) of ethyl 5-(p-chlorobenzoyl)-1-methylpyrrole-2-acetate in 60 ml. of ether is added to a suspension of 1.25 g. (0.032 mole) of sodamide in 150 ml. of refluxing liquid ammonia. After 10 minutes, 4.98 g. (0.032 mole) of ethyl iodide is added. The mixture is stirred for 1.5 hours, and an additional 1.0 g. (0.0064 mole) of ethyl iodide is added. Stirring is continued for 30 minutes and ammonium chloride is then added to neutralize any anion. The mixture is allowed to warm to room temperature and the ammonia allowed to escape. Ether is added, and the mixture poured into dilute hydrochloric acid. The ether layer is separated, and the aqueous layer is washed with ether. The combined ether solutions are washed successively with sodium bisulfite solution and brine and then dried over anhydrous magnesium sulfate. The solvent is evaporated in vacuo to give about 7.4 g. of a yellow oily residue containing ethyl 5-(p-chlorobenzoyl)-α-ethyl-1-methylpyrrole-2-acetate, which is used as such in the following transformation to acid procedure. A 6.9 g. sample of the oily residue is dissolved in 30 ml. of ethanol and 11.4 ml. of 1N sodium hydroxide is added. The mixture is refluxed for 1 hour. The solvent is then evaporated in vacuo, and the residue partitioned between ether and water. The aqueous layer is separated and acidified with dilute hydrochloric acid. The precipitated oil, which is separated, crystallizes on scratching to give a solid, 5-(p-chlorobenzoyl)-α-ethyl-1-methylpyrrole-2-acetic acid, which is collected and dried, m.p. 108-112° C. After successive recrystallizations from ether-methylcyclohexane, benzene-hexane, methylcyclohexane and ether-hexane, the m.p. is 110-114° C. Analysis: Calcd. for C16H16ClNO3 : C, 62.84; H, 5.27; N, 4.58% Found: C, 63.01; H, 5.36; N, 4.61%

Provenance & Evidence