5-bromo-6-methylquinolin-2-ol synthesis

Yield:1016316-14-5 81%

Reaction Conditions:

Stage #1: 5-bromo-6-methylquinoline 1-oxidewith trifluoroacetic anhydride in N,N-dimethyl-formamide at 0 - 20;
Stage #2: with water;sodium hydrogencarbonate in N,N-dimethyl-formamide;

Steps:

9

Intermediate 9: 5-bromo-6-methyl-2(1 H)-quinolinone Trifluoroacetic anhydride (48.5 ml, 348.6 mmol) was added to a solution of 5-bromo- 6-methylquinoline 1-oxide (Intermediate 8) (16.6 g, 69.7 mmol) in DMF (46 ml) at O⁰C. The reaction mixture was stirred at room temperature overnight, then poured into saturated aqueous NaHCO₃ (600 ml). The resulting precipitate was filtered off and triturated with diethyl ether to give the title compound (13.5 g, 81 %); MS: (ES) m/z: 238, 240 [MH⁺]. C₁₀H₈BrNO requires 238.08; ¹H-NMR (400 MHz, CDCI₃) δ: 11.92 (br.s., 1 H)₁ 8.08 (d, 1 H), 7.47 (d, 1 H), 7.24 (d, 1 H), 6.60 (d, 1 H), 2.42 (s, 3 H).

References:

WO2008/37681,2008,A1 Location in patent:Page/Page column 44-45