Ethyl diazoacetate → Ethyl 5-benzyl-4,6-dioxo-1,3a,4,5,6,6a-hexahydropyrrolo[3,4-c]pyrazole-3-carboxylate

HRID 373694

Reaction equation

HRID 373694 reaction equation
[N+:1](=[CH:3][C:4]([O:6][CH2:7][CH3:8])=[O:5])=[N-:2].[CH2:9]([N:16]1[C:20](=[O:21])[CH:19]=[CH:18][C:17]1=[O:22])[C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1>C(OCC)C>[CH2:9]([N:16]1[C:20](=[O:21])[CH:19]2[CH:18]([NH:2][N:1]=[C:3]2[C:4]([O:6][CH2:7][CH3:8])=[O:5])[C:17]1=[O:22])[C:10]1[CH:11]=[CH:12][CH:13]=[CH:14][CH:15]=1

Participants

4

Reactant 2

HCID 12192Ethyl diazoacetateHCID 74204Benzylmaleimide

Product 1

HCID 2857138Ethyl 5-benzyl-4,6-dioxo-1,3a,4,5,6,6a-hexahydropyrrolo[3,4-c]pyrazole-3-carboxylateYield 100%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent2×

Procedure

Ethyl diazoacetate (13 g, 114 mmol) in diethyl ether (100 ml) was added dropwise to a solution of N-benzylmaleimide (10 g, 53 mmol) in diethyl ether (250 ml). The resulting mixture was allowed to stir for 18 hours; the solvent was then removed in vacuo, and the resulting residue partitioned between methylene chloride and water. The organic layer was dried over sodium sulfate, filtered and concentrated to provide the title product as a white solid, mp 145°-146° with decomposition (16 g, 53 mmol, 100% yield). 1H NMR (CDCl3): 7.31 (m, 5H), 7.02 (bs, 1H), 4.89 (dd, J=11, 2 Hz, 1H), 4.65 (s, 2H), 4.55 (d, J=10 Hz, 1H), 4.36 (q, J=7 Hz, 2H), 1.37 (t, J=7 Hz, 3H).

Workup

  1. customthe solvent was then removed in vacuo
  2. customthe resulting residue partitioned between methylene chloride and water
  3. dry with materialThe organic layer was dried over sodium sulfate
  4. filtrationfiltered
  5. concentrationconcentrated

Sources & evidence

ORD record
ord-1bf83f3744b64d53af9c0e93171c4542
Source dataset
uspto-grants-1992_11
Patent number
US05164402

Linked notes

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