1-methyl-2-phenylquinolin-4(1H)-one 11: 1.75 g (0.01 mol); phenylhydrazine hydrochloride 4: 1.43 g (0.01 mol); Yield: 1.98 g (80%);
The primary topics include three and four-membered heterocycles, five-membered heterocycles including indoles, furans, thiophenes, and oxazoles, six-membered heterocycles including quinolines, isoquinolines, and pyrimidines, and other heterocycles.
Preparation of 4-hydroxy-1-methylquinolin-2(1H)-one 3a
In a round-bottomed flask 4-hydroxy-2-phenylquinoline 10 (0.1 mol), DMF (15 ml), Me2SO4 (2 ml) and NaH (500 mg) were heated at reflux in a microwave oven at 120°C in 250 watts for 5 minutes. The brown monitored by TLC. After complete conversion, the product was poured into 1000 ml of cold water; the precipitate formed was filtered, dried and purified with column chromatography using petroleum ether as eluting solvent. The yield was 70%.
9.3 Combes quinoline synthesis.
14 In our continuing effort in discovering new synthetic methodologies for heterocycles 15 under microwave condition, 15i–k we herein report Zn(OTf) 2 catalyzed preparative method for substituted quinolines under microwave condition.
9.5 Doebner quinoline synthesis.
9 Recent revelation in the synthesis of quinoline derivatives has revealed that metal-catalyzed coupling cyclizations of appropriate precursors could compete with classical synthesis in terms of efficacy and rapidity of the quinoline construction.
9.11 Pfitzinger quinoline synthesis.
0.01 mol of 4-(2-hydroxyanilino)-2-phenylquinoline 19b in p-TSA was subjected to heat at 120°C for 8 hours in heating mantle. The reaction completion is confirmed by TLC and the reaction mixture was cooled and poured into 1000 mL cold water, filtered and purified by column chromatography using chloroform and methanol (95:5) as eluting solvent system.
9.16 Riehm quinoline synthesis.
A mixture of 15 (0.50 g, 0.0012 mol), triphenylphosphine (0.06 g, 0.0023 mol), palladium(II) acetate (0.03 g, 0.0001 mol) and sodium hydrogen carbonate (0.31 g, 0.0037 mol) and tricaprylmethylammoniumchloride as phase transfer catalysis was refluxed in water at 100°C for 5 minute, with 300 watts in the microwave oven. The mixture was allowed to cool to room temperature, poured into water and then acidified to pH 2–3 with dilute hydrochloric acid. The mixture was extracted several times with ethyl acetate and the combined organic extracts were washed with water, dried with anhydrous sodium sulphate, filtered and evaporated under reduced pressure giving 6-phenyl-11H-indolo[3,2-c]quinoline 16.
Combes quinoline synthesis - Wikipedia
0.01 mol 4-chloro-2-phenylquinoline 17, and 0.01 mol of respective aniline (7a&b) hydrochloride were dissolved in tertiary butanol and refluxed at 80°C. After one hour the colourless solution yield yellow solid. The heating is further continued for 1-2h. Excess of solvent was distilled, cooled to room temperature and poured into 1000 mL of ice cold water. The yellow solid was filtered, dried and recrystallized with methanol.