Benzyl piperazine-1-carboxylate → 4-[5-(4-(benzyloxycarbonyl)piperazin-1-yl)pyridin-2-yl]-3,4-dihydro-2H-quinoxaline-1-carboxylic acid tert-butyl ester

HRID 1510047Notes

Reaction equation

HRID 1510047 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](Br)=[CH:20][N:19]=2)[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].[CH2:25]([O:32][C:33]([N:35]1[CH2:40][CH2:39][NH:38][CH2:37][CH2:36]1)=[O:34])[C:26]1[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=1.C1(P(C2CCCCC2)C2C=CC=CC=2C2C(OC)=CC=CC=2OC)CCCCC1.CC(C)([O-])C.[Na+]>C1(C)C=CC=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.[Pd].[Pd].C(OCC)(=O)C>[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:38]3[CH2:37][CH2:36][N:35]([C:33]([O:32][CH2:25][C:26]4[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=4)=[O:34])[CH2:40][CH2:39]3)=[CH:20][N:19]=2)[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2]

Participants

8

Reactant 4

HCID 643495Benzyl piperazine-1-carboxylateHCID 112698722-Dicyclohexylphosphino-2',6'-dimethoxybiphenylHCID 23676156Sodium t-butoxideHCID 668635404-(5-bromopyridin-2-yl)-3,4-dihydro-2H-quinoxaline-1-carboxylic acid tert-butyl ester

Product 1

HCID 668631914-[5-(4-(benzyloxycarbonyl)piperazin-1-yl)pyridin-2-yl]-3,4-dihydro-2H-quinoxaline-1-carboxylic acid tert-butyl esterYield 74.1%

Reagents, catalysts & solvents 3

HCID 9811564Bis(dibenzylideneacetone)palladiumCatalystHCID 1140TolueneSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
110 °C

Procedure

10.12 g of 4-(5-bromopyridin-2-yl)-3,4-dihydro-2H-quinoxaline-1-carboxylic acid tert-butyl ester and 5.7 g of 4-(benzyloxycarbonyl)piperazine are placed in 118 ml of toluene and then 0.95 g of tris(dibenzylideneacetone)dipalladium(0), 1.7 g of 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl and 3.5 g of sodium tert-butoxide are added. The reaction medium is heated at 110° C. for 3 h. Ethyl acetate is subsequently added and the mixture is washed once with water and once with a saturated aqueous sodium chloride solution. The organic phase is dried over magnesium sulphate and concentrated under reduced pressure. The crude product obtained is chromatographed on silica gel, elution being carried out with a gradient of a mixture of heptane/ethyl acetate (90/10 to 0/100). 10.16 g of 4-[5-(4-(benzyloxycarbonyl)piperazin-1-yl)pyridin-2-yl]-3,4-dihydro-2H-quinoxaline-1-carboxylic acid tert-butyl ester are obtained.

Workup

  1. washthe mixture is washed once with water and once with a saturated aqueous sodium chloride solution
  2. dry with materialThe organic phase is dried over magnesium sulphate
  3. concentrationconcentrated under reduced pressure
  4. customThe crude product obtained
  5. customis chromatographed on silica gel, elution
  6. additionbeing carried out with a gradient of a mixture of heptane/ethyl acetate (90/10 to 0/100)

Sources & evidence

ORD record
ord-d9258741eb2d4b86b2c6ebcf6a126c8e
Source dataset
uspto-grants-2012_07
Patent number
US08211892B2

Reaction notes

Loading…