6-Bromo-3-nitro-4-quinolinol

5-Bromo-2-(2-nitrovinylamino)benzoic acid (Compound of step 1, 25 g, 87 mmol) and potassium acetate (10.5 g, 104 mmol) in acetic anhydride (112 mL, 1185 mmol) were stirred for 3 hours at 120 Compound 6 (15 g, 0.052 mol) and potassium acetate (6.16 g, 0.063 mol) in acetic anhydride (100 mL) were stirred for 1.5 h at 120Synthesis of Compound 3a (29.0 g, 0.130 mol)Add to a 500 mL three-necked flask, Heat and stir until dissolved.Further, a mixture of nitric acid (40.95 g, 0.650 mol) and propionic acid (10 mL) was slowly added dropwise to the reaction flask.After the addition is completed, the reaction is further carried out for 2 hours.TLC detection [V (dichloromethane): V (methanol) = 15:1] The reaction was completed, cooled, filtered, The filter residue is added to the ice saturated sodium bicarbonate solution and stirred.Filtered, The residue is dry, The compound was obtained as a yellow solid (26.0 g, yield: 64.5percent).The solution of compound 2g (20 mmol, 4.48 g) in propionic acid (30 mL) was heated to 125 ℃ and the mixture of nitric acid (0.89 mL) and propionic acid (6.27 mL) was added dropwise for 1 h. Then the mixture was reacted for 1 h and precipitated by petroleum ether. The solid was filtered and washed with diethyl ether. Yield 50.2percent. HPLC purity: 98.1percent.Further cyclization yields compound 2-7.10556] The above reaction scheme illustrates the synthesis of a compound of the invention 2-13. Methylation of starting material 2-1 yields compound 2-2, which is subsequently reduced to the amine 2-3. In a separate reaction, compound 2-4 is converted to a salt, such as an HC1 salt, which is then reacted, for example, with 2-nitrovinyl-hydroxylamine to yield compound 2-6. Further cyclization yields compound 2-7. Halogenation with a reagent such as POd3 results in compound 2-8, which can be coupled with intermediate 2-3 to yield 2-9. The nitro moiety of 2-9 is subsequently reduced to an amine, and a further reaction with 4-nitrophenyl carbonochloridate results in the heterocycle 2-11. The desired compound 2-13 is then prepared by coupling to the benzoxazolyl boronate 2-12, for example in a Suzuki coupling.[0073] 50.25 g (0.175 mole) of Intermediate 1 was placed in a 500-ml single-necked flask, added with 250 ml of aceticanhydride, heated to 60°C, followed by the addition of 18.2 g (0.23 mol) of potassium acetate. Then the temperaturewas raised to 110°C, and the mixture was reacted. The reaction was monitored by TLC. After 4 h, the mixture wasallowed to cool to room temperature, filtered, and washed with acetic acid to be colorless, to give 26.8 g of Intermediate2 as a white solid. Yield: 56percent.50.25 g (0.175 mol) of Intermediate 1 was placed in a 500 ml single-neck flask, 250 ml of acetic anhydride was added, The temperature was increased to 60 ° C, and 18.2 g (0.23 mol) of potassium acetate was added. The reaction was warmed to 110 ° C and monitored by TLC.After 4h, the mixture was cooled to room temperature, filtered and washed with acetic acid until colorless.

Molecular Weight:269.05
XLogP3:2.3
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:4
Exact Mass:267.94835
Monoisotopic Mass:267.94835
Topological Polar Surface Area:74.9
Heavy Atom Count:15
Complexity:337
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes