Sulfuric Acid → tert-Butyl 4-methyl-3,4-dihydroquinoline-1(2H)-carboxylate

HRID 2290094Notes

Reaction equation

HRID 2290094 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)([CH3:18])[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].OS(O)(=O)=O>C(OCC)(=O)C.[Pd]>[C:1]([O:5][C:6]([N:8]1[C:17]2[C:12](=[CH:13][CH:14]=[CH:15][CH:16]=2)[CH:11]([CH3:18])[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:2])[CH3:3]

Participants

5

Reactant 2

HCID 1118Sulfuric AcidHCID 234334501-Tert-butyloxycarbonyl-1,2,3,4-tetrahydro4-hydroxy-4-methylquinoline

Product 1

HCID 23433524tert-Butyl 4-methyl-3,4-dihydroquinoline-1(2H)-carboxylateYield 92%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 8857Ethyl AcetateSolvent

Procedure

A solution of 1-tert-Butyloxycarbonyl-1,2,3,4-tetrahydro-4-hydroxy-4-methylquinoline (109 mg, 0.41 mmol) in ethyl acetate (3 mL) was hydrogenated under an atmosphere of hydrogen with 10% Pd/C (10 mg) and a trace of conc. H2SO4 at rt for 7 h. Filtration over Celite™ afforded 93 mg (92%) of 1-tert-butyloxycarbonyl-1,2,3,4-tetrahydro-4-methylquinoline. Data for 1-tert-butyloxycarbonyl-1,2,3,4-tetrahydro-4-methylquinoline: 1H NMR (400 MHz, CDCl3) 7.62 (d, J=8.1, 1H), 7.16 (d, J=7.8, 1H), 7.11 (ddd, J=7.8, 7.8, 1.6, 1H), 7.01 (ddd, J=7.7, 7.5, 1.0, 1H), 3.71 (m, 2H), 2.87 (ddq, J=6.8, 6.8, 6.8, 1H), 2.04 (ddd, J=7.4, 7.4, 7.4, 6.1, 1H), 1.61 (m, 1H), 1.51 (s, 9H), 1.3 (d, J=6.8, 3H).

Workup

  1. filtrationFiltration over Celite™

Sources & evidence

ORD record
ord-e50f1d3bf891432f91b73392bc95e5c4
Source dataset
uspto-grants-2000_07
Patent number
US06093821

Reaction notes

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