Methyl chloroformate → Ethyl benzoate

Participants

Reaction Conditions

Reaction Steps

6.5 g of 2-butoxy-nicotinic acid (melting point= m.p. 54°-56° C., from acetic acid ethyl ester) are dissolved in 150 ml of tetrahydrofuran. After addition of 14.5 ml of triethylamine, the batch is cooled to 0° C., and 3.2 ml of chloroformic acid methyl ester are added dropwise. Agitation is continued for one hour at 0° C., 7.6 g of 4-(2-aminoethyl)-benzoic acid ethyl ester-hydrochloride are added, agitation is continued for a further hour at 0° C., and subsequently for 4 hours at room temperature. The batch is evaporated and the residue is combined with acetic acid ethyl ester. After washing with water, sodium bicarbonate solution, dilute hydrochloric acid and water, the acetic acid ethyl ester solution is dried and evaporated under reduced pressure. The 4-(2-<2-butoxy-nicotin-amido>-ethyl)-benzoic acid ethyl ester so obtained is refluxed for 3 hours in 25 ml of 2 N sodium hydroxide solution and 50 ml of ethanol. After having distilled off the solvent, the product is dissolved in water and acidified with dilute acetic acid, suction-filtered and recrystallized from acetic ester. The 4-(2-<2-butoxy-nicotin-amido>-ethyl)-benzoic acid has a melting point of 147°-149° C.

Provenance & Evidence