Dimethyl acetylenedicarboxylate → 2-(Methoxycarbonyl)-4-oxo-6,8-dichloro-7-methylquinoline

HRID 982935Notes

Reaction equation

[Cl:1][C:2]1[C:7]([NH2:8])=[CH:6][CH:5]=[C:4]([Cl:9])[C:3]=1[CH3:10].[C:11]([C:17](OC)=[O:18])#[C:12][C:13]([O:15][CH3:16])=[O:14]>CO>[CH3:16][O:15][C:13]([C:12]1[CH2:11][C:17](=[O:18])[C:6]2[C:7](=[C:2]([Cl:1])[C:3]([CH3:10])=[C:4]([Cl:9])[CH:5]=2)[N:8]=1)=[O:14]

Participants

Conditions

Temperature: 235 °C

Procedure

To a solution of 2,6-dichloro-3-aminotoluene (20.5 g, 0.11 mol) in methanol (300 mL) was added dimethyl acetylenedicarboxylate (15 mL, 0.12 mol) and the reaction mixture was refluxed for 2 hours. The reaction mixture was concentrated under reduced pressure to a yellow solid. Diphenyl ether (350 mL) was heated to 230-240° C., and the yellow solid was added to it. The temperature was maintained at 230-240° C. for 20 minutes and the reaction mixture was cooled slowly to ambient temperature and diluted with petroleum ether (1 L). The solid was filtered and washed with hot ethyl acetate to afford a brown solid, 2-(methoxycarbonyl)-4-oxo-6,8-dichloro-7-methylquinoline (28.5 g, 85%); NMR (CDCl3) 2.62 (s, 3), 4.04 (s, 3), 7.02 (s, 1), 8.24 (s, 1) ppm.

Workup

temperaturethe reaction mixture was refluxed for 2 hours
concentrationThe reaction mixture was concentrated under reduced pressure to a yellow solid
additionthe yellow solid was added to it
temperatureThe temperature was maintained at 230-240° C. for 20 minutes
temperaturethe reaction mixture was cooled slowly to ambient temperature
additiondiluted with petroleum ether (1 L)
filtrationThe solid was filtered
washwashed with hot ethyl acetate

Sources & evidence

ORD record: ord-490b25c11066447f94cb671a2bef7219
Source dataset: uspto-grants-2005_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06861424B2

Reaction notes

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