Methyl 3,3-dimethyl-2-(4-nitrophenyl)-1,2,3,4-tetrahydroquinoline-6-carboxylate → Methyl 2-(4-aminophenyl)-3,3-dimethyl-1,2,3,4-tetrahydroquinoline-6-carboxylate

HRID 1801287Notes

Reaction equation

HRID 1801287 reaction equation
[CH3:1][O:2][C:3]([C:5]1[CH:6]=[C:7]2[C:12](=[CH:13][CH:14]=1)[NH:11][CH:10]([C:15]1[CH:20]=[CH:19][C:18]([N+:21]([O-])=O)=[CH:17][CH:16]=1)[C:9]([CH3:25])([CH3:24])[CH2:8]2)=[O:4]>CO.O.[Fe]>[NH2:21][C:18]1[CH:17]=[CH:16][C:15]([CH:10]2[C:9]([CH3:24])([CH3:25])[CH2:8][C:7]3[C:12](=[CH:13][CH:14]=[C:5]([C:3]([O:2][CH3:1])=[O:4])[CH:6]=3)[NH:11]2)=[CH:20][CH:19]=1

Participants

4

Reactant 1

HCID 67441375Methyl 3,3-dimethyl-2-(4-nitrophenyl)-1,2,3,4-tetrahydroquinoline-6-carboxylate

Product 1

HCID 67441380Methyl 2-(4-aminophenyl)-3,3-dimethyl-1,2,3,4-tetrahydroquinoline-6-carboxylateYield 96%

Reagents, catalysts & solvents 2

HCID 23925IronCatalystHCID 22242641Methanol--water (1/1)Solvent

Procedure

To a solution of methyl 4-hydroxy-3,3-dimethyl-2-(4-nitrophenyl)-1,2,3,4-tetrahydroquinoline-6-carboxylate (61 mg 0.18 mmol) and triethylsilane (0.06 mL, 0.34 mmol) in dichloromethane (10 mL) was added dropwise a solution of trifluoroacetic acid (0.04 mL, 0.51 mol) in dichloromethane (5 mL) below 0° C. Upon completion of addition, the resultant mixture was stirred at room temperature for 24 h, then was quenched with sodium bicarbonate solution and separated. The organic layer was dried over anhydrous sodium sulfate and concentrated. The residue was purified by column chromatography to afford 50 mg of methyl 3,3-dimethyl-2-(4-nitrophenyl)-1,2,3,4-tetrahydroquinoline-6-carboxylate as a yellow solid Yield: 78%. Methyl-3,3-dimethyl-2-(4-nitrophenyl)-1,2,3,4-tetrahydroquinoline-6-carboxylate (110 mg, 0.32 mmol) was dissolved in methanol/water Solution, iron powder (25 mg, 3.2 mmol) was added. The reaction mixture was heated to reflux for 2 hrs The mixture was filtered, the filtration was concentrated and purified by column chromatography on silica gel (petroleum ether/ethyl acetate=4:1) to afford 95 mg of methyl 2-(4-aminophenyl)-3,3-dimethyl-1,2,3,4-tetrahydroquinoline-6-carboxylate as a yellow solid. (yield: 96%). MS (ESI+APCI) M+1=311.5.

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureto reflux for 2 hrs The mixture
  3. filtrationwas filtered
  4. filtrationthe filtration
  5. concentrationwas concentrated
  6. custompurified by column chromatography on silica gel (petroleum ether/ethyl acetate=4:1)

Sources & evidence

ORD record
ord-0e34499a668f4ef98eeb98e384d4058e
Source dataset
uspto-grants-2013_01
Patent number
US08344137B2

Reaction notes

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