Hydrochloric Acid → HCID 178422421, compound

Participants

Reaction Steps

The title compound of Step B (11.75 g, 37.29 mmol) was suspended in a mixture of isopropanol (120 mL) and water (120 mL) at room temperature under a nitrogen atmosphere. A solution of sodium hydroxide (14.91 g of a 50% aqueous solution, 186.4 mmol) diluted with water (10 mL) was added dropwise to the mixture over 30 min. The mixture was allowed to stir at room temperature overnight. First, 1N hydrochloric acid and then concentrated hydrochloric acid were added dropwise to the reaction mixture until the pH was approximately 2. Solids were filtered from the reaction mixture. These solids were washed with water and then cold ethyl acetate to afford the title compound of Step C as a reddish-brown solid melting at 241°-243° C. (8.67 g, 91%). 1H NMR ((CD3)2SO): δ2.47 (s,3H), 7.69 (s, 1H), 7.81 (s, 1H), 8.12 (s, 1H), 8.9 (br s, 1H).

Provenance & Evidence