Phosphorus tribromide → Ethyl 2-(2-bromoethyl)-4-(3,4-dimethoxyphenyl)-6,7-dimethoxyquinoline-3-carboxylate

HRID 266126Notes

Reaction equation

P(Br)(Br)[Br:2].[CH3:5][O:6][C:7]1[CH:8]=[C:9]([C:15]2[C:24]3[C:19](=[CH:20][C:21]([O:27][CH3:28])=[C:22]([O:25][CH3:26])[CH:23]=3)[N:18]=[C:17]([CH2:29][CH2:30]O)[C:16]=2[C:32]([O:34][CH2:35][CH3:36])=[O:33])[CH:10]=[CH:11][C:12]=1[O:13][CH3:14].C(=O)(O)[O-].[Na+]>C1C=CC=CC=1>[Br:2][CH2:30][CH2:29][C:17]1[C:16]([C:32]([O:34][CH2:35][CH3:36])=[O:33])=[C:15]([C:9]2[CH:10]=[CH:11][C:12]([O:13][CH3:14])=[C:7]([O:6][CH3:5])[CH:8]=2)[C:24]2[C:19](=[CH:20][C:21]([O:27][CH3:28])=[C:22]([O:25][CH3:26])[CH:23]=2)[N:18]=1

Participants

Conditions

Temperature: 80 °C

Procedure

Phosphorus tribromide (1.0 g) was added dropwise to a solution of ethyl 4-(3,4-dimethoxyphenyl)-2-(2-hydroxyethyl)-6,7-dimethoxyquinoline-3-carboxylate (1.7 g) in benzene (50 ml) at room temperature. The mixture was stirred at 80° C. for 1 hour, poured into ice-cold water, neutralized with an aqueous saturated solution of sodium bicarbonate, and then extracted with chloroform. The chloroform layer was washed with water, dried over magnesium sulfate, and the solvent was evaporated under reduced pressure. The residue was subjected to column chromatography on silica gel. The fractions eluted with chloroform-ethyl acetate (1:1, v/v) gave ethyl 2-(2-bromoethyl)-4-(3,4-dimethoxyphenyl)-6,7-dimethoxyquinoline-3-carboxylate (0.49 g, 26%). This was recrystallized from ethyl acetate-hexane. Colorless prisms, mp. 132°-133° C.

Workup

additionpoured into ice-cold water
extractionextracted with chloroform
washThe chloroform layer was washed with water
dry with materialdried over magnesium sulfate
customthe solvent was evaporated under reduced pressure
washThe fractions eluted with chloroform-ethyl acetate (1:1

Sources & evidence

ORD record: ord-75d24a1588e846398464d7d5961438a9
Source dataset: uspto-grants-1997_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05650410

Reaction notes

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