HCID 131711786, compound → HCID 14067395, compound

Participants

Reaction Steps

5.4 g (17.5 mmol) of the 4H-8-chloro-2-methoxycarbonyl-imidazo-[2,1-c][1,4]-benzoxazine-1-carboxylic acid prepared in Step E were stirred in 50 ml of Dowtherm A on an oil bath. The solution obtained bubbled vigorously when the oil bath reached 185°-195° C. When the effervescence had ceased, the solution was cooled and diluted with ether. The product crystallized out and was filtered off, washed well with ether and dried under vacuum over P2O5 to obtain 4.4 g (95% yield) of methyl 8-chloro-4H-imidazo-[2,1-c][1,4]-benzoxazine-2-carboxylate with a melting point of 239°-40° C. in the form of off-white needles.

Provenance & Evidence