反应详情

In a modification of the method described in JCS Perkin Trans. I 1972, 2584, a mixture of 2-hydroxy-hexanoic acid ethyl ester (5 g, 31 mmol), N-bromosuccinimide (12 g, 67 mmol) and catalytic AIBN in anhydrous CCl4 (60 mL) is refluxed. After heating for about 20 minutes, the reaction initiates with evolution of a red-brown gas. After refluxing 4 hours, the resulting mixture is filtered and the filtrate evaporated at reduced pressure to obtain 3-bromo-2-oxo-hexanoic acid ethyl ester as a dark liquid. Step 2. Preparation of 3-(1-propyl)-imidazolo[1,2-a]pyridine-2-carboxylate

1. temperatureis refluxed
2. temperatureAfter heating for about 20 minutes
3. temperatureAfter refluxing 4 hours
4. filtrationthe resulting mixture is filtered
5. customthe filtrate evaporated at reduced pressure