Reaction #61067

Reaction equation

Et3N

4-methoxy-2-methylaniline

KOt-Bu

4-chlorobutyryl chloride

→

title compound

Yield 92.0%

1-(4-Methoxy-2-methylphenyl)pyrrolidin-2-one

Yield 92.0%

Solvents

THF

Water

THF

THF

Conditions

Workup

1. 1
   TemperatureThe internal temperature was maintained at circa 10° C.
2. 2
   Otherthe internal temperature <10° C
3. 3
   workup.STIRRINGThe reaction mixture was stirred at that temperature for 30 min
4. 4
   Otherthe phases were separated
5. 5
   workup.ADDITIONThe organic layer was treated with conc. HCl (250 mL) and water (1.26 L)
6. 6
   Otherthe phases were separated
7. 7
   ExtractionThe combined aqueous layers were extracted with EtOAc (2.6 L)
8. 8
   Washthe combined organic layers were washed with brine (2 L)
9. 9
   OtherThe solvent was evaporated
10. 10
    Otherthe residue purified by flash chromatography (Biotage 150, EtOAc/cHex 8:2)

Procedure

To a solution of Et3N (156 mL, 1 eq) and 4-methoxy-2-methylaniline (150 g, 1.09 mole) in anh. THF (2.4 L), in a 10 L reaction vessel, at 0° C., under N2, was added dropwise a solution of 4-chlorobutyryl chloride (126 mL, 1 eq) in anh. THF (480 mL). The internal temperature was maintained at circa 10° C. and the reaction mixture was stirred for 1.5 hr. It was cooled down to 0° C. and KOt-Bu 1M/THF (2.64 L, 2.4 eq) was added dropwise over a period of 1.5 hr, keeping the internal temperature <10° C. The reaction mixture was stirred at that temperature for 30 min. Water (1.5 L) was then added slowly (20 min) and the phases were separated. The organic layer was treated with conc. HCl (250 mL) and water (1.26 L) and the phases were separated. The combined aqueous layers were extracted with EtOAc (2.6 L) and the combined organic layers were washed with brine (2 L). The solvent was evaporated and the residue purified by flash chromatography (Biotage 150, EtOAc/cHex 8:2) to give the title compound as a pale brown solid (206 g, 92%).

Source