Potassium Carbonate → 2-(4-Bromo-2-fluorobenzyl)-4-(-)-menthyloxycarbonyl-1,3-dioxo-1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazine-4-acetic acid tert-butyl ester

HRID 256592Notes

Reaction equation

HRID 256592 reaction equation
[CH:1]1([CH3:33])[CH2:6][CH2:5][CH:4]([CH:7]([CH3:9])[CH3:8])[CH:3]([O:10][C:11]([CH:13]2[N:18]3[CH:19]=[CH:20][CH:21]=[C:17]3[C:16](=[O:22])[N:15]([CH2:23][C:24]3[CH:29]=[CH:28][C:27]([Br:30])=[CH:26][C:25]=3[F:31])[C:14]2=[O:32])=[O:12])[CH2:2]1.C(=O)([O-])[O-].[K+].[K+].Br[CH2:41][C:42]([O:44][C:45]([CH3:48])([CH3:47])[CH3:46])=[O:43]>CN(C)C=O>[C:45]([O:44][C:42](=[O:43])[CH2:41][C:13]1([C:11]([O:10][CH:3]2[CH:4]([CH:7]([CH3:8])[CH3:9])[CH2:5][CH2:6][CH:1]([CH3:33])[CH2:2]2)=[O:12])[N:18]2[CH:19]=[CH:20][CH:21]=[C:17]2[C:16](=[O:22])[N:15]([CH2:23][C:24]2[CH:29]=[CH:28][C:27]([Br:30])=[CH:26][C:25]=2[F:31])[C:14]1=[O:32])([CH3:48])([CH3:47])[CH3:46]

Participants

5

Reactant 3

HCID 11430Potassium CarbonateHCID 79177tert-Butyl bromoacetateHCID 867473472-(4-Bromo-2-fluorobenzyl)-1,3-dioxo-1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazine-4-carboxylic acid (-)-menthyl ester

Product 1

HCID 677225582-(4-Bromo-2-fluorobenzyl)-4-(-)-menthyloxycarbonyl-1,3-dioxo-1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazine-4-acetic acid tert-butyl ester

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
70 °C

Procedure

A mixture of 2-(4-bromo-2-fluorobenzyl)-1,3-dioxo-1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazine-4-carboxylic acid (-)-menthyl ester (67.0 g), anhydrous potassium carbonate (36.0 g) and tert-butyl bromoacetate (33.0 g) in anhydrous dimethylformamide (200 ml) was stirred under the stream of nitrogen at 70° C. for 2.5 hours. After removal of the insoluble materials by filtration, the filtrate was poured into water and extracted with ethyl acetate. The extracts were washed with saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate, and evaporated under reduced pressure. The residue was recrystallized from n-hexane to give the title compound (Diastereomer A) (23.5 g, 28.8%) as colorless crystals, mp 99°-100° C.

Workup

  1. customAfter removal of the insoluble materials
  2. filtrationby filtration
  3. additionthe filtrate was poured into water
  4. extractionextracted with ethyl acetate
  5. washThe extracts were washed with saturated aqueous sodium chloride solution
  6. dry with materialdried over anhydrous sodium sulfate
  7. customevaporated under reduced pressure
  8. customThe residue was recrystallized from n-hexane

Sources & evidence

ORD record
ord-7ea79379214647d1805da693ef93ec4c
Source dataset
uspto-grants-1993_11
Patent number
US05258382

Reaction notes

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