Bromine → Methyl 3,8-dibromo-5-methoxyquinoline-6-carboxylate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

step 1—Bromine (4.48 mL, 86.9 mmol) in HOAc (50 mL) was added to a solution of 2-bromoacrylaldehyde (11.7 g, 86.9 mmol, CASRN 111049-68-4) in HOAc (100 mL) at RT until the solution showed faint Br2 color. To this solution was added methyl 4-amino-5-bromo-2-methoxybenzoate (22.6 g, 86.9 mmol) and the resulting solution was gradually heated to 100° C. After the temperature reached 100° C., stirring was continued for 15 min then the solution was cooled and concentrated in vacuo. The reaction mixture was neutralized with satd. aq. NaHCO3 and the resulting solid was filtered and washed with water. The solid was washed with ether followed by 10% MeOH/DCM to afford 11.04 g of 122a. The filtrate was absorbed onto SiO2 and purified on a flash column eluting with a DCM/hexane gradient (50 to 100% DCM to afford an additional 3.46 g of 122a.

Herkunft & Nachweise