Ammonium formate → 4-(4-(piperazin-1-yl)phenyl)-3,4-dihydro-2H-quinoxaline-1-carboxylic acid tert-butyl ester

HRID 41696Notes

Reaction equation

HRID 41696 reaction equation
[C:1]([O:5][C:6]([N:8]1[C:17]2[C:12](=[CH:13][CH:14]=[CH:15][CH:16]=2)[N:11]([C:18]2[CH:23]=[CH:22][C:21]([N:24]3[CH2:29][CH2:28][N:27](C(OCC4C=CC=CC=4)=O)[CH2:26][CH2:25]3)=[CH:20][CH:19]=2)[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].C([O-])=O.[NH4+]>[Pd].CO>[C:1]([O:5][C:6]([N:8]1[C:17]2[C:12](=[CH:13][CH:14]=[CH:15][CH:16]=2)[N:11]([C:18]2[CH:23]=[CH:22][C:21]([N:24]3[CH2:29][CH2:28][NH:27][CH2:26][CH2:25]3)=[CH:20][CH:19]=2)[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:2])[CH3:3]

Participants

5

Reactant 2

HCID 2723923Ammonium formateHCID 668635804-[4-(4-(Benzyloxycarbonyl)piperazin-1-yl)phenyl]-3,4-dihydro-2H-quinoxaline-1-carboxylic acid tert-butyl ester

Product 1

HCID 668633984-(4-(piperazin-1-yl)phenyl)-3,4-dihydro-2H-quinoxaline-1-carboxylic acid tert-butyl esterYield 95.7%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 887MethanolSolvent2×

Procedure

3.5 g of 4-[4-(4-(benzyloxycarbonyl)piperazin-1-yl)phenyl]-3,4-dihydro-2H-quinoxaline-1-carboxylic acid tert-butyl ester are placed in a 250 ml three-necked flask under an inert atmosphere. 66 ml of MeOH, then 1.67 g of ammonium formate followed by 1.41 g of 10% Pd/C (50% in water), are added. The mixture is brought to reflux of the methanol for 1 h 30 minutes and then brought back to ambient temperature. It is filtered on a Whatman filter under an inert atmosphere and then rinsing is carried out numerous times with methanol. The methanol is evaporated under reduced pressure. The mixture is taken up in dichloromethane and the organic phase is washed with the minimum amount of water. The organic phase is dried over sodium sulphate, filtered through a sintered glass filter and evaporated under reduced pressure. 2.5 g of 4-(4-(piperazin-1-yl)phenyl)-3,4-dihydro-2H-quinoxaline-1-carboxylic acid tert-butyl ester are obtained in the form of a white solid.

Workup

  1. additionare added
  2. custombrought back to ambient temperature
  3. filtrationIt is filtered on a Whatman
  4. filtrationfilter under an inert atmosphere
  5. washrinsing
  6. customThe methanol is evaporated under reduced pressure
  7. washthe organic phase is washed with the minimum amount of water
  8. dry with materialThe organic phase is dried over sodium sulphate
  9. filtrationfiltered through a sintered glass
  10. filtrationfilter
  11. customevaporated under reduced pressure

Sources & evidence

ORD record
ord-c285a11d9d6346678754a8bad1ca37d2
Source dataset
uspto-grants-2013_09
Patent number
US08530657B2

Reaction notes

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