Sodium Hydroxide → 4-Amino-6-methoxyquinoline-3-carboxylic acid

HRID 1466969Notes

Reaction equation

[NH2:1][C:2]1[C:11]2[C:6](=[CH:7][CH:8]=[C:9]([O:12][CH3:13])[CH:10]=2)[N:5]=[CH:4][C:3]=1[C:14]([O:16]CC)=[O:15].[OH-].[Na+]>CCO>[NH2:1][C:2]1[C:11]2[C:6](=[CH:7][CH:8]=[C:9]([O:12][CH3:13])[CH:10]=2)[N:5]=[CH:4][C:3]=1[C:14]([OH:16])=[O:15]

Participants

Conditions

Temperature: 0 °C

Procedure

To a stirred solution of ethyl 4-amino-6-methoxyquinoline-3-carboxylate (Example 1a, 1.23 g, 5.0 mmol) in EtOH (20.0 mL) was added aqueous NaOH (2.0 N, 5.0 mL) at room temperature. The reaction mixture was then refluxed for 3 hr. The solution was then filtered and washed with water. The filtrate was cooled to 0° C. and neutralized carefully with 1 N HCl to pH 7. Most of the EtOH was removed under reduced pressure, and the precipitate was collected by filtration, washed with cold water, and dried under vacuum to give the title compound as an off-white solid (1.01 g, 93%). 1H NMR (400 MHz, DMSO-d6) δ 3.89 (s, 3H), 7.40 (dd, J=2.8, 9.4 Hz, 1H), 7.73 (d, J=9.4 Hz, 1H), 7.77 (d, J=2.8 Hz, 1H), 8.77 (s, 1H). MS 219 (MH+).

Workup

temperatureThe reaction mixture was then refluxed for 3 hr
filtrationThe solution was then filtered
washwashed with water
customMost of the EtOH was removed under reduced pressure
filtrationthe precipitate was collected by filtration
washwashed with cold water
customdried under vacuum

Sources & evidence

ORD record: ord-762e5f6f12a7435bb9d34702e1bfd3f4
Source dataset: uspto-grants-2015_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09000054B2

Reaction notes

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