Isopropylamine → HCID 22341128, compound

Participants

Reaction Steps

To a stirred suspension of 6,7-dichloroquinoxaline-2,3-diol (1.0 g, 4.3 mmol) in concentrated sulfuric acid (20 ml) at 0° C. was added sodium nitrate (554 mg, 6.5 mmol) in portions over 15 minutes. The reaction mixture was stirred overnight at room temperature. The reaction was quenched by slowly pipetting into ice water. The precipitate was collected by vacuum filtration and the beige solid was washed with water. The nitrated product was suspended in phosphorous oxychloride, about 6 ml of DMF was added to make it homogeneous and the reaction was heated at reflux overnight. The reaction was quenched by slowly pipetting into ice water. The aqueous mixture was then extracted twice with ethyl acetate. The organic layers were combined and concentrated in vacuo to a beige solid. To a solution of the chlorinated product (1.57 g, crude) in DMF was added caesium carbonate (2.36 g, 7.2 mmol) followed by isopropyl amine (0.31 ml). The reaction mixture was stirred overnight at room temperature. The solvent was removed in vacuo. The solid was taken up in water and ethyl acetate. The layers were separated and the aqueous layer was extracted twice with ethyl acetate. The organic layers were combined and concentrated to a yellow solid that was purified by flash column chromatography using ethyl acetate:hexane 1:10. To a solution of the aminated product (588 mg, 1.7 mmol) in DMF (20 ml) was added methanesulfinic acid sodium salt (215 mg, 2.1 mmol). The solution was stirred overnight at room temperature. The final product was purified by flash column chromatography using ethyl acetate:hexane 1:5 obtaining the title compound as a yellow solid.

Provenance & Evidence