Benzophenone imine → 3-(Benzhydrylidene-amino)-1-methyl-pyrrolidin-2-one

HRID 626874Notes

Reaction equation

HRID 626874 reaction equation
[C:1](=[NH:14])([C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.N[CH:16]1[CH2:20][CH2:19][N:18]([CH3:21])[C:17]1=[O:22]>ClCCCl>[C:1](=[N:14][CH:16]1[CH2:20][CH2:19][N:18]([CH3:21])[C:17]1=[O:22])([C:8]1[CH:9]=[CH:10][CH:11]=[CH:12][CH:13]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

4

Reactant 2

HCID 136809Benzophenone imineHCID 457911333-Amino-1-methylpyrrolidin-2-one

Product 1

HCID 896489983-(Benzhydrylidene-amino)-1-methyl-pyrrolidin-2-oneYield 88.7%

Reagents, catalysts & solvents 1

HCID 111,2-DichloroethaneSolvent

Conditions

Temperature
95 °C

Procedure

Benzophenone imine (200.04 g, 1103.8 mmol) was added dropwise over 20 minutes to a stirred solution of 3-amino-1-methylpyrrolidine-2-one (120 g, 1051.2 mmol) in DCE (1000 mL) at ambient temp under nitrogen in a 2 L flask fitted with a magnetic stirrer bar. The reagent was washed with further DCE (100 mL). The stirred solution was heated at reflux on a heat-on block at a block temp of 95° C. for 7 h, using a N2 bubbler with exhaled gas passing through a safety trap then into 2 L of water via an upturned funnel (for scrubbing NH3 gas, estimated to be approx 23 L). The reaction was left to stand at ambient temp overnight under N2. The mixture was evaporated to a thick, off-white oil. To this was added Et2O (700 ml) and to this stirred solution, as it began to crystallize, was added iso-hexane (700 ml) over 2 minutes. The mixture was stirred for 1 h then filtered under suction and washed with Et2O/iso-hexane (1:1) (500 ml). The white solid was dried at 35° C. under vacuum for 3 h to afford 3-(benzhydrylidene-amino)-1-methyl-pyrrolidin-2-one (D1) (259.4 g, 88.6%). The NMR was consistent with pure material.

Workup

  1. customfitted with a magnetic stirrer bar
  2. washThe reagent was washed with further DCE (100 mL)
  3. temperatureThe stirred solution was heated
  4. waitThe reaction was left
  5. customThe mixture was evaporated to a thick, off-white oil
  6. additionTo this was added Et2O (700 ml)
  7. customto crystallize
  8. additionwas added iso-hexane (700 ml) over 2 minutes
  9. filtrationthen filtered under suction
  10. washwashed with Et2O/iso-hexane (1:1) (500 ml)
  11. customThe white solid was dried at 35° C. under vacuum for 3 h

Sources & evidence

ORD record
ord-74d9836d15ce49a399e22f2aa1c1fcdb
Source dataset
uspto-grants-2016_04
Patent number
US09309254B2

Reaction notes

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