Lithium diisopropylamide → Tert-butyl 3-methyl-4-oxo-1,2,3,4-tetrahydroquinoline-1-carboxylate

HRID 2294491Notes

Reaction equation

HRID 2294491 reaction equation
[C:1]([O:5][C:6]([N:8]1[C:17]2[C:12](=[CH:13][CH:14]=[CH:15][CH:16]=2)[C:11](=[O:18])[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].[Li+].[CH3:20]C([N-]C(C)C)C>C1COCC1>[C:1]([O:5][C:6]([N:8]1[C:17]2[C:12](=[CH:13][CH:14]=[CH:15][CH:16]=2)[C:11](=[O:18])[CH:10]([CH3:20])[CH2:9]1)=[O:7])([CH3:4])([CH3:2])[CH3:3]

Participants

4

Reactant 2

HCID 2724682Lithium diisopropylamideHCID 23433504tert-Butyl 4-oxo-3,4-dihydroquinoline-1(2H)-carboxylate

Product 1

HCID 23433478Tert-butyl 3-methyl-4-oxo-1,2,3,4-tetrahydroquinoline-1-carboxylateYield 23%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-78 °C

Procedure

To a solution of 1-tert-butyloxycarbonyl-1,2,3,4-tetrahydro-4-quinolinone (structure 68A of Scheme LI, where R1-2 =H) (EXAMPLE 325) (500 mg, 0.002 mol) in THF (5 mL) at -78° C. was added 2.0M LDA in THF (1.01 mL, 0.002 mol). The reaction mixture was stirred at -78° C. for 15 min and iodomethylane (126 mL, 0.002 mol) was added all at once. The temperature was raised to 0° C. and the resulting mixture stirred for 4 h. The reaction was then quenched with sat'd NH4Cl (5 mL), extracted with ethyl acetate (2×10 mL), dried (Na2SO4) and concentrated in vacuo to a solid residue that was subjected to flash column chromatography (silica gel, hexanes/ethyl acetate, 95:5) to give 117 mg (23%) of 1-tert-butyloxycarbonyl-1,2,3,4-tetrahydro-3-methyl-4-quinolinone (structure 69A of Scheme LI, where R1-2 =H, R3 =methyl), 128 mg (23%) of 1-tert-butyloxycarbonyl-1,2,3,4-tetrahydro-3,3-dimethyl-4-quinolinone (structure 70A of Scheme LII, where R1-2 =H, R3-4 =methyl) and 200 mg (40%) of recovered starting material. Data for 1-tert-butyloxycarbonyl-1,2,3,4-tetrahydro-3-methyl-4-quinolinone: 1 H NMR (400 MHz, CDCl3) 7.99 (dd, J=7.9, 1.7, 1H), 7.77 (d, J=8.4, 1H), 7.48 (ddd, J=7.3, 7.3, 1.7, 1H), 7.13 (dd, J=7.4, 1.0, 1H), 4.32 (dd, J=13.4, 4.4, 1H), 3.69 (dd, J=13.3, 9.8, 1H), 2.76 (ddd, J=9.8, 7.0, 4.4, 1H), 1.56 (s, 9H), 1.24 (d, J=7.0, 3H).

Workup

  1. additioniodomethylane (126 mL, 0.002 mol) was added all at once
  2. temperatureThe temperature was raised to 0° C.
  3. stirringthe resulting mixture stirred for 4 h
  4. customThe reaction was then quenched with sat'd NH4Cl (5 mL)
  5. extractionextracted with ethyl acetate (2×10 mL)
  6. dry with materialdried (Na2SO4)
  7. concentrationconcentrated in vacuo to a solid residue that

Sources & evidence

ORD record
ord-72a7183d268545109e23a5b708e33881
Source dataset
uspto-grants-1997_11
Patent number
US05688810

Reaction notes

Loading…