Selenium Dioxide → 4-Chloro-9H-dipyrido[2,3-b;4',3'-d]pyrrole-6-carboxylic acid methyl ester

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Reaction Conditions

Reaction Steps

A mixture of 4-chloro-6,7,8,9-tetrahydro-5H-dipyrido[2,3-b;4′,3′-d]pyrrole-6-carboxylic acid methyl ester (2.1 g, 7.9 mmol) and selenium dioxide (1.20 g, 11.1 mol) in 1,4-dioxane (50 mL) was heated at 100° C. for 3.5 hours. The resulting grey slurry was filtered whilst hot through a pad of celite and the pad washed with hot THF and 25% methanol in dichloromethane. The combined filtrate was concentrated in-vacuo and the resultant residue triturated with methanol (10 mL). The resultant solid was collected by filtration and left to air dry to afford the title compound as an off white solid (1.03 g, 48%). 1H NMR (400 MHz, DMSO-d6): 13.02 (s, 1H), 9.06 (d, J=1.1 Hz, 1H), 8.94 (d, J=1.0 Hz, 1H), 8.63 (d, J=5.3 Hz, 1H), 7.54 (d, J=5.3 Hz, 1H), 3.93 (s, 3H).

Provenance & Evidence