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ChemicalBook CAS DataBase List 2(1H)-Quinoxalinone, 7-fluoro-3,4-dihydro-
66367-11-1

2(1H)-Quinoxalinone, 7-fluoro-3,4-dihydro- synthesis

3synthesis methods
-

Yield:66367-11-1 72%

Reaction Conditions:

with iron;acetic acid at 20 - 30;Inert atmosphere;

Steps:

7

Preparation of 7-fluoro-3 ,4-dihvdro-iH-quinoxalin-2-one: Iron powder (6.52 g, 116.8 mmol, 5.0 eq) is added at room temperature to a stirred solution of (4-fluoro-2-nitro-phenylamino)-acetic acid (6.85 g, 23.4 mmol, 1.0 eq) in glacial acetic acid (40 mL). The resulting suspension is heated at 90 0C for 3 hours, then cooled to room temperature, diluted with ethyl acetate (40 mL), and filtered through silica gel. The filtrate is concentrated to give a crude that is purified by column chromatography (silica gel, eluent: ethyl acetate.'petroleum ether, 1:3, v/v) to afford 7-fluoro-3,4-dihydro-iH- quinoxalin-2-one as a brown solid (4.01 g, 72% yield). 1H-NMR (400 MHz, DMSO-t/6) δ ppm: 10.28 (s, IH), 6.63-6.51 (m, 3H), 5.87 (s, IH),3.66 (d, J = 2.0 Hz, 2H).MS m/z (+ESI): 167.1 [M+H]+.

References:

WO2010/84152,2010,A1 Location in patent:Page/Page column 54-55