5-amino-3,4-dihydro-4-hydroxy-4-(trifluoromethyl)-1H-quinolin-2-one → 5-hydroxy-4-(trifluoromethyl)-1H-quinolin-2-one

HRID 1350133Notes

Reaction equation

N[C:2]1[CH:11]=[CH:10][CH:9]=[C:8]2[C:3]=1[C:4](O)([C:13]([F:16])([F:15])[F:14])[CH2:5][C:6](=[O:12])[NH:7]2.N([O-])=[O:19].[Na+]>OS(O)(=O)=O.O>[OH:19][C:2]1[CH:11]=[CH:10][CH:9]=[C:8]2[C:3]=1[C:4]([C:13]([F:16])([F:15])[F:14])=[CH:5][C:6](=[O:12])[NH:7]2

Participants

Conditions

Temperature: 145 °C

Procedure

To a solution of 5-amino-3,4-dihydro-4-hydroxy-4-(trifluoromethyl)-1H-quinolin-2-one (6.0 g, 24 mmol) in 100 mL 4.8 M H2SO4 was added a solution of NaNO2 (1.85 g, 26.8 mmol) in 6 mL water at 0° C. The reaction mixture became deep red. This solution was transferred to 120 mL 10M H2SO4 preheated to 145° C. The mixture was heated at 145° C. for 0.5 h, then poured into 400 g of ice water. The crude solid was adsorbed onto silica gel and eluted with 9:1 CH2Cl2:MeOH to afford 4.6 g (82%) of 5-hydroxy-4-(trifluoromethyl)-1H-quinolin-2-one, an off-white solid. 1H NMR (400 MHz, acetone-d6) δ 11.0 (broad s, 1H), 9.64 (s, 1H), 7.42 (t, 1H, J=8.1), 6.99 (d, 1H, J=8.1), 6.90 (s, 1H), 6.79 (d, 1H, J=8.1).

Workup

custompreheated to 145° C
washeluted with 9:1 CH2Cl2

Sources & evidence

ORD record: ord-a819b254aea3457586cc87849cf66048
Source dataset: uspto-grants-2007_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07214690B2

Reaction notes

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