Sodium Hydroxide → HCID 14067394, compound

Participants

Reaction Steps

The methyl 8-chloro-4H-imidazo-[2,1-c][1,4]-benzoxazine-2-carboxylate prepared in Example 1 was suspended in 50 ml of ethanol and a solution of 1.15 g (29 mmol) of sodium hydroxide in 50 ml of water was added thereto. The mixture obtained was then heated on a steam bath until a clear solution was obtained and thin layer chromatography indicated no starting ester remaining. The solution was filtered and the filtrate was acidified while still hot to a pH of 2-3 with concentrated hydrochloric acid. On cooling, the acid crystallized out and was collected, was washed with water and dried over P2O5 under vacuum to obtain 3.20 g (97% yield) of 8-chloro-4H-imidazo-[2,1-c][1,4]-benzoxazine-2-carboxylic acid in the form of colorless needles with a melting point of 276°-278° C.

Provenance & Evidence