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

HRID 1801286Notes

Reaction equation

HRID 1801286 reaction equation
O[CH:2]1[C:11]2[C:6](=[CH:7][CH:8]=[C:9]([C:12]([O:14][CH3:15])=[O:13])[CH:10]=2)[NH:5][CH:4]([C:16]2[CH:21]=[CH:20][C:19]([N+:22]([O-:24])=[O:23])=[CH:18][CH:17]=2)[C:3]1([CH3:26])[CH3:25].C([SiH](CC)CC)C.FC(F)(F)C(O)=O>ClCCl>[CH3:25][C:3]1([CH3:26])[CH2:2][C:11]2[C:6](=[CH:7][CH:8]=[C:9]([C:12]([O:14][CH3:15])=[O:13])[CH:10]=2)[NH:5][CH:4]1[C:16]1[CH:17]=[CH:18][C:19]([N+:22]([O-:24])=[O:23])=[CH:20][CH:21]=1

Participants

5

Reactant 3

HCID 6422Trifluoroacetic acidHCID 12052TriethylsilaneHCID 67443026Methyl 4-hydroxy-3,3-dimethyl-2-(4-nitrophenyl)-1,2,3,4-tetrahydroquinoline-6-carboxylate

Product 1

HCID 67441375Methyl 3,3-dimethyl-2-(4-nitrophenyl)-1,2,3,4-tetrahydroquinoline-6-carboxylateYield 81.6%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

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. additionUpon completion of addition
  2. customwas quenched with sodium bicarbonate solution
  3. customseparated
  4. dry with materialThe organic layer was dried over anhydrous sodium sulfate
  5. concentrationconcentrated
  6. customThe residue was purified by column chromatography

Sources & evidence

ORD record
ord-4c1ca8d45bb54762b2906f3eeb1ebb73
Source dataset
uspto-grants-2013_01
Patent number
US08344137B2

Reaction notes

Loading…