N-bromobutanimide → 1-PIPERAZINECARBOXYLIC ACID, 4-(5-BROMOPYRAZINYL)-, 1,1-DIMETHYLETHYL ESTER

HRID 592784Notes

Reaction equation

HRID 592784 reaction equation
[N:1]1[CH:6]=[CH:5][N:4]=[CH:3][C:2]=1[N:7]1[CH2:12][CH2:11][N:10]([C:13]([O:15][C:16]([CH3:19])([CH3:18])[CH3:17])=[O:14])[CH2:9][CH2:8]1.[Br:20]N1C(=O)CCC1=O>C(#N)C>[Br:20][C:5]1[N:4]=[CH:3][C:2]([N:7]2[CH2:8][CH2:9][N:10]([C:13]([O:15][C:16]([CH3:19])([CH3:18])[CH3:17])=[O:14])[CH2:11][CH2:12]2)=[N:1][CH:6]=1

Participants

4

Reactant 2

HCID 67184N-bromobutanimideHCID 21069279HCID 21069279, compound

Product 1

HCID 210692801-PIPERAZINECARBOXYLIC ACID, 4-(5-BROMOPYRAZINYL)-, 1,1-DIMETHYLETHYL ESTERYield 94.4%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

A 500-mL single-neck round-bottomed flask equipped with a magnetic stirrer and a reflux condenser was charged with acetonitrile (150 mL), 189a (3.0 g, 8.8 mmol), and N-bromosuccinimide (1.56 g, 8.8 mmol). The mixture was stirred at room temperature overnight. It was then concentrated under reduced pressure and the resulting residue was purified by silica-gel column chromatography eluting with 10:1 petroleum ether/ethyl acetate to afford 189b as a yellow solid (2.85 g, 73.4%). MS: [M+H]+ 343.3. 1H NMR (500 MHz, (CD3)2CO) δ 8.03 (s, 1H), 7.94 (s, 1H), 3.48-3.46 (m, 4H), 3.42-3.40 (m, 4H), 1.33 (s, 9H).

Workup

  1. customA 500-mL single-neck round-bottomed flask equipped with a magnetic stirrer and a reflux condenser
  2. concentrationIt was then concentrated under reduced pressure
  3. customthe resulting residue was purified by silica-gel column chromatography
  4. washeluting with 10:1 petroleum ether/ethyl acetate

Sources & evidence

ORD record
ord-ba86fe508d72471c9fc589fed6149710
Source dataset
uspto-grants-2016_01
Patent number
US09238655B2

Reaction notes

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