Water → 2-(5-Bromo-pyridin-3-yl)-4-hydroxy-3,3-dimethyl-1,2,3,4-tetrahydro-quinoline-6-carboxylic acid ethyl ester

HRID 1801147Notes

Reaction equation

[CH2:1]([O:3][C:4](=[O:20])[C:5]1[CH:10]=[CH:9][C:8]([N:11]=[CH:12][C:13]2[CH:14]=[N:15][CH:16]=[C:17]([Br:19])[CH:18]=2)=[CH:7][CH:6]=1)[CH3:2].[CH:21](=[O:25])[CH:22]([CH3:24])[CH3:23].O>O1CCCC1.O.[O-]S(C(F)(F)F)(=O)=O.[Yb+3].[O-]S(C(F)(F)F)(=O)=O.[O-]S(C(F)(F)F)(=O)=O>[CH2:1]([O:3][C:4]([C:5]1[CH:10]=[C:9]2[C:8](=[CH:7][CH:6]=1)[NH:11][CH:12]([C:13]1[CH:14]=[N:15][CH:16]=[C:17]([Br:19])[CH:18]=1)[C:22]([CH3:24])([CH3:23])[CH:21]2[OH:25])=[O:20])[CH3:2]

Participants

Conditions

Temperature: 25 °C

Procedure

To a mixture of 4-[(5-bromo-pyridin-3-ylmethylene)-amino]-benzoic acid ethyl ester (33.8 g, 100 mmol) and Ytterbium(III) triflate hydrate (6.2 g, 10 mmol) in dry tetrahydrofuran (100 mL) at 25° C. was added isobutyraldehyde (9.2 mL, 100 mmol) and water (1.8 mL, 100 mmol) dropwise. The reaction mixture was stirred at 25° C. for 16 h. Then the reaction mixture was concentrated in vacuo and the residue was extracted with ethyl acetate (2×200 mL), washed with brine, dried over anhydrous sodium sulfate and concentrated in vacuo to afford 2-(5-bromo-pyridin-3-yl)-4-hydroxy-3,3-dimethyl-1,2,3,4-tetrahydro-quinoline-6-carboxylic acid ethyl ester (42.2 g, quant.) as a light yellow oil which was used for next step without further purification: LC/MS m/e calcd for C19H21BrN2O3 (M+H)+: 406.29, observed: 405.0 & 406.9.

Workup

concentrationThen the reaction mixture was concentrated in vacuo
extractionthe residue was extracted with ethyl acetate (2×200 mL)
washwashed with brine
dry with materialdried over anhydrous sodium sulfate
concentrationconcentrated in vacuo

Sources & evidence

ORD record: ord-ab4e1888ca8f40fe8e5ec9d1947e6eca
Source dataset: uspto-grants-2013_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08344137B2

Reaction notes

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