Diketene → diethyl N-(2,4-dimethoxybenzyl)-3-hydroxy-3-methyl-5-oxo-2,2-pyrrolidine-dicarboxylate

HRID 1719665Notes

Reaction equation

HRID 1719665 reaction equation
[CH3:1][O:2][C:3]1[CH:21]=[C:20]([O:22][CH3:23])[CH:19]=[CH:18][C:4]=1[CH2:5][NH:6][CH:7]([C:13]([O:15][CH2:16][CH3:17])=[O:14])[C:8]([O:10][CH2:11][CH3:12])=[O:9].[CH2:24]=[C:25]1[O:29][C:27](=[O:28])[CH2:26]1>C(O)(=O)C>[CH3:1][O:2][C:3]1[CH:21]=[C:20]([O:22][CH3:23])[CH:19]=[CH:18][C:4]=1[CH2:5][N:6]1[C:27](=[O:28])[CH2:26][C:25]([OH:29])([CH3:24])[C:7]1([C:8]([O:10][CH2:11][CH3:12])=[O:9])[C:13]([O:15][CH2:16][CH3:17])=[O:14]

Participants

4

Reactant 2

HCID 12661DiketeneHCID 13422978Diethyl {[(2,4-dimethoxyphenyl)methyl]amino}propanedioate

Product 1

HCID 13422981diethyl N-(2,4-dimethoxybenzyl)-3-hydroxy-3-methyl-5-oxo-2,2-pyrrolidine-dicarboxylateYield 60%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

39.6 g (0.122 moles) of diethyl (2,4-dimethoxybenzyl-amino)-malonate prepared according to Example (1c) are boiled with 12.3 g (11.2 ml, 0.146 moles) of diketene in 80 ml of glacial acetic acid for half an hour. The glacial acetic acid is distilled off on a water bath, in vacuo; the residual oil is crystallized by trituration with 150 ml of water, whereupon the substance is dissolved in 60 ml of ethyl acetate and recrystallized by addition of petroleum ether. 29.6 g (60%) of diethyl N-(2,4-dimethoxybenzyl)-3-hydroxy-3-methyl-5-oxo-2,2-pyrrolidine-dicarboxylate and/or the tautomer thereof are obtained.

Workup

  1. distillationThe glacial acetic acid is distilled off on a water bath, in vacuo
  2. customthe residual oil is crystallized by trituration with 150 ml of water, whereupon the substance
  3. dissolutionis dissolved in 60 ml of ethyl acetate
  4. customrecrystallized by addition of petroleum ether

Sources & evidence

ORD record
ord-8def80484fb14562b04719554df516c4
Source dataset
uspto-grants-1985_09
Patent number
US04541955

Reaction notes

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