Triethylamine → 3-Ethoxycarbonyl-1-(2-fluoroethyl)-7,8,9-trifluoro-4-oxo-1,4-dihydrobenzo[b][1,8]naphthyridine

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Reaction Steps

3-Ethoxycarbonyl-1-(2-fluoroethyl)-7,8,9-trifluoro-4-oxo-1,4-dihydrobenzo[b][1,8]naphthyridine was prepared under conditions similar to Example 3, but starting with ethyl 2-(2-chloro-6,7,8-trifluoro-3-quinolinecarbonyl)(dimethylamino)acrylate (3.9 g), 2-fluoroethylamine hydrochloride (3 g) and triethylamine (4.2 cc) in ethanol (100 cc). After the addition of DBU (1.8 cc), the solution is heated for 2 hours to 80° C. After the same treatment of the reaction mixture as in Example 24, 3-ethoxycarbonyl-7,8,9-trifluoro-1-(2-fluoroethyl)-4-oxo-1,4-dihydrobenzo[b][1,8]naphthyridine (2.8 g) is obtained in the form of a yellow solid, m.p. 302°-304° C.

Provenance & Evidence