Reaction #80816

Reaction equation

iodomethane

N-trifluoroacetyl-2-methoxycarbonyltetrahydroquinoline

potassium

toluene

→

2-methyl-N-trifluoroacetyl-2-methoxycarbonyltetrahydroquinoline

Yield 98.0%

Solvents

water

THF

Conditions

Workup

1. 1
   workup.STIRRINGstirred 5 h
2. 2
   Extractionextracted with ethyl acetate
3. 3
   WashThe extract was washed with water and brine
4. 4
   Dryingdried over magnesium sulfate
5. 5
   Concentrationconcentrated

Procedure

To a solution of N-trifluoroacetyl-2-methoxycarbonyltetrahydroquinoline (8.7 g, 30.3 mmol)in THF (100 mL) was added slowly 0.5N potassium hexamethylsilazide in toluene (66.6 mL, 33.3 mmol) over 15 min at -78° C. The mixture was stirred for 10 min followed by addition of iodomethane (2.3 mL, 36.4 mmol) at the same temperature. The mixture was allowed to warm to room temperature, stirred 5 h, poured into water, and extracted with ethyl acetate. The extract was washed with water and brine, dried over magnesium sulfate, and concentrated to give 8.98 g of 2-methyl-N-trifluoroacetyl-2-methoxycarbonyltetrahydroquinoline (98%): 1H NMR (270 MHz, CDCl3) δ7.18 (m, 3H), 7.07 (m, 1H), 3.71 (s, 3H), 2.90 (td, 1H, J=13.9, 3.3 Hz), 2.50 (dt, 1H, J=13.9, 3.3 Hz), 2.28 (dt, 1H, J=13.9, 3.3 Hz), 1.56 (s, 3H), 1.53 (td, 1H, J=13.9, 3.3 Hz).

Source