Hydrochloric Acid → 1-[5-(4-Cyclopropanesulfonyl-piperazin-1-yl)pyridin-2-yl]-1,2,3,4-tetrahydroquinoxaline

HRID 41973Notes

Reaction equation

HRID 41973 reaction equation
[CH:1]1([S:4]([N:7]2[CH2:12][CH2:11][N:10]([C:13]3[CH:14]=[CH:15][C:16]([N:19]4[C:28]5[C:23](=[CH:24][CH:25]=[CH:26][CH:27]=5)[N:22](C(O)=O)[CH2:21][CH2:20]4)=[N:17][CH:18]=3)[CH2:9][CH2:8]2)(=[O:6])=[O:5])[CH2:3][CH2:2]1.Cl.C([O-])(O)=O.[Na+]>O1CCOCC1.ClCCl>[CH:1]1([S:4]([N:7]2[CH2:8][CH2:9][N:10]([C:13]3[CH:14]=[CH:15][C:16]([N:19]4[C:28]5[C:23](=[CH:24][CH:25]=[CH:26][CH:27]=5)[NH:22][CH2:21][CH2:20]4)=[N:17][CH:18]=3)[CH2:11][CH2:12]2)(=[O:6])=[O:5])[CH2:3][CH2:2]1

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 516892Sodium BicarbonateHCID 687351314-[5-(4-cyclopropanesulfonyl-piperazin-1-yl)pyridin-2-yl]-3,4-dihydro-2H-quinoxaline-1-carboxylic acid

Product 1

HCID 668634841-[5-(4-Cyclopropanesulfonyl-piperazin-1-yl)pyridin-2-yl]-1,2,3,4-tetrahydroquinoxaline

Reagents, catalysts & solvents 2

HCID 6344DichloromethaneSolvent2×HCID 312751,4-DioxaneSolvent

Procedure

6.14 g of tert-butyl ester of 4-[5-(4-cyclopropanesulfonyl-piperazin-1-yl)pyridin-2-yl]-3,4-dihydro-2H-quinoxaline-1-carboxylic acid is put in a 1-liter three-necked flask under nitrogen atmosphere. 102 ml of dichloromethane is added, it is cooled in an ice bath and 92 ml of a 4M solution of hydrochloric acid in dioxane is added dropwise. The temperature of the reaction mixture is allowed to return slowly to room temperature and then it is stirred for 5 h. The reaction mixture is diluted with dichloromethane, then cooled in an ice bath. Then a saturated solution of NaHCO3 is added to pH=8. It is decanted and the aqueous phase is extracted with dichloromethane. The water-based organic phases are washed, dried over Na2SO4, filtered on a frit and concentrated. 4.92 g of 1-[5-(4-cyclopropanesulfonyl-piperazin-1-yl)pyridin-2-yl]-1,2,3,4-tetrahydroquinoxaline is obtained in the form of a white solid.

Workup

  1. temperatureit is cooled in an ice bath
  2. customto return slowly to room temperature
  3. temperaturecooled in an ice bath
  4. customIt is decanted
  5. extractionthe aqueous phase is extracted with dichloromethane
  6. washare washed
  7. dry with materialdried over Na2SO4
  8. filtrationfiltered on a frit
  9. concentrationconcentrated

Sources & evidence

ORD record
ord-d790e4b875104f5b8f7c313786488f15
Source dataset
uspto-grants-2013_09
Patent number
US08536173B2

Reaction notes

Loading…