Isobutylene → 2-(2-Ethyl-phenyl)-4,4-dimethyl-1,2,3,4-tetrahydro-quinoline-6-carboxylic acid methyl ester

HRID 2408061Notes

Reaction equation

[CH3:1][O:2][C:3](=[O:11])[C:4]1[CH:9]=[CH:8][C:7]([NH2:10])=[CH:6][CH:5]=1.[CH2:12]([C:14]1[CH:21]=[CH:20][CH:19]=[CH:18][C:15]=1[CH:16]=O)[CH3:13].[CH2:22]=[C:23]([CH3:25])[CH3:24].FC(F)(F)S([O-])(=O)=O.[Yb+3].FC(F)(F)S([O-])(=O)=O.FC(F)(F)S([O-])(=O)=O>C(#N)C.C(OCC)(=O)C>[CH3:1][O:2][C:3]([C:4]1[CH:5]=[C:6]2[C:7](=[CH:8][CH:9]=1)[NH:10][CH:16]([C:15]1[CH:18]=[CH:19][CH:20]=[CH:21][C:14]=1[CH2:12][CH3:13])[CH2:22][C:23]2([CH3:25])[CH3:24])=[O:11]

Participants

Conditions

Temperature: 85 °C

Procedure

To a stirred solution of 4-amino-benzoic acid methyl ester (1 g, 6 mmol) and 2-ethyl-benzaldehyde (1.2 g, 8.9 mmol) in acetonitrile (40 mL) were added isobutene (1.7 mL, 24 mmol) and ytterbium(III) trifluoromethanesulfonate (Yb(OTf)3) (0.55 g, 0.9 mmol). The resulting mixture was stirred at 85° C. for 16 h in sealed tube. The mixture was diluted with ethyl acetate (100 mL) and washed with water (50 mL×2) and brine (50 mL×2) and then dried over anhydrous sodium sulfate. The solvent was removed in vacuo and the residue was purified by ISCO combi-flash chromatography (gradient elution, 10-50% ethyl acetate in petroleum ether) to afford 2-(2-ethyl-phenyl)-4,4-dimethyl-1,2,3,4-tetrahydro-quinoline-6-carboxylic acid methyl ester (1 g, 49%) as a light yellow solid: MS (ESI) M+1=337.0.

Workup

washwashed with water (50 mL×2) and brine (50 mL×2)
dry with materialdried over anhydrous sodium sulfate
customThe solvent was removed in vacuo
customthe residue was purified by ISCO combi-flash chromatography (gradient elution, 10-50% ethyl acetate in petroleum ether)

Sources & evidence

ORD record: ord-b81300de80a1405d8561830447f0830f
Source dataset: uspto-grants-2014_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08809369B2

Reaction notes

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