Ethylene Glycol → HCID 15617190, compound

Participants

Reaction Steps

A mixture of N-[3-[[3-(trifluoromethyl)benzoyl]amino]-2-pyridinyl]glycine ethyl ester (22.0 g, 0.06 mole) and ethylene glycol (100 ml) was heated at reflux for 40 minutes. The reaction mixture was poured into water (300 ml) and cooled. The solid was collected by filtration, washed with water (200 ml), and dried. The solid was recrystallized from isopropyl ether-tetrahydrofuran to give in 2 crops 18.4 g (0.053 mole) of crude 2-(3-trifluoromethylphenyl)-3H-imidazo[4,5-b]pyridine-3-acetic acid ethyl ester. This solid together with potassium hydroxide pellets (4.7 g, 0.084 mole), 95% ethanol (150 ml), and water (10 ml) was refluxed for 21/2 hrs. The reaction mixture was cooled to room temperature and concentrated in vacuo. The residue was dissolved in water (100 ml) and extracted with methylene chloride (2×30 ml). The aqueous portion was acidified with glacial acetic acid and filtered after precipitation was complete. The filter cake was suspended in water (200 ml) and filtered. Recrystallization from tetrahydrofuran-isopropyl ether gave 15.3 g (91%). A 1.6-g sample was recrystallized from tetrahydrofuran-isopropyl ether to give 1.0 g of an off-white solid, mp 240°-241.5° C.

Provenance & Evidence