Ethane, 1-chloro-2-ethoxy- → 3H-Imidazo(4,5-b)pyridine-2-ethanamine, N,N-dimethyl-3-(2-ethoxyethyl)-

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Reaction Steps

A mixture formed by 3.9 g 2,3-diaminopyridine and 6.1 g 3-dimethylaminopropionic acid hydrochloride in 40 g polyphosphoric acid, is heated at 160° C. for 5 hours. Reaction mixture is cooled to room temperature, dissolved in water, then made alkaline adjusting the pH to 10 with NaOH and extracted several times with chloroform. Organic extracts are collected together, evaporated to dryness and the residue, crystallized from acetonitrile, gives 1.4 g 2-(2-dimethylaminoethyl)-3H-imidazo [4,5-b] pyridine melting at 109°-112° C. Operation is further processed as described in Example 1 using 2-(2-dimethylaminoethyl)-3H-imidazo [4,5-b] pyridine and 2-ethoxyethyl chloride and after purification by chromatography on silicagel column (CHCl3 --CH3OH 9:1), 3-(2-ethoxyethyl)-2-(2-dimethylaminoethyl)-3H-imidazo [4,5-b] pyridine is obtained as an oil with a yield of 17%.

Provenance & Evidence