Water → tert-butyl 8-carbamoyl-6-chloro-7-phenyl-3,4-dihydropyrrolo[1,2-a]pyrazine-2(1H)-carboxylate

HRID 1630011Notes

Reaction equation

HRID 1630011 reaction equation
Br[C:2]1[C:3]([C:19](=[O:21])[NH2:20])=[C:4]2[CH2:9][N:8]([C:10]([O:12][C:13]([CH3:16])([CH3:15])[CH3:14])=[O:11])[CH2:7][CH2:6][N:5]2[C:17]=1[Cl:18].[C:22]1(B(O)O)[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1.O.C(=O)([O-])[O-].[Cs+].[Cs+]>O1CCCC1.C1C=CC(P(C2C=CC=CC=2)[C-]2C=CC=C2)=CC=1.C1C=CC(P(C2C=CC=CC=2)[C-]2C=CC=C2)=CC=1.Cl[Pd]Cl.[Fe+2].ClCCl>[C:19]([C:3]1[C:2]([C:22]2[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=2)=[C:17]([Cl:18])[N:5]2[CH2:6][CH2:7][N:8]([C:10]([O:12][C:13]([CH3:16])([CH3:15])[CH3:14])=[O:11])[CH2:9][C:4]=12)(=[O:21])[NH2:20]

Participants

8

Reactant 4

HCID 962WaterHCID 10796Cesium carbonateHCID 66827Phenylboronic AcidHCID 66585083tert-butyl 7-bromo-8-carbamoyl-6-chloro-3,4-dihydropyrrolo[1,2-a]pyrazine-2(1H)-carboxylate

Product 1

HCID 66584861tert-butyl 8-carbamoyl-6-chloro-7-phenyl-3,4-dihydropyrrolo[1,2-a]pyrazine-2(1H)-carboxylateYield 40%

Reagents, catalysts & solvents 3

HCID 178418228Bis(cyclopenta-1,4-dien-1-yl(diphenyl)phosphane);dichloropalladium;iron(2+)CatalystHCID 6344DichloromethaneSolventHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
100 °C

Procedure

To a solution under nitrogen of 3.78 g (9.98 mmol) of tert-butyl 7-bromo-8-carbamoyl-6-chloro-3,4-dihydropyrrolo[1,2-a]pyrazine-2(1H)-carboxylate in 160 ml of tetrahydrofuran are added 1.34 g (11.0 mmol) of benzeneboronic acid (CAS 98-80-6), 8 ml of water, 9.76 g (30.0 mmol) of caesium carbonate and 0.98 g (1.20 mmol) of a complex of 1,1′-bis(diphenylphosphino)ferrocenedichloropalladium (II) and dichloromethane (PdCl2(dppf).CH2Cl2—CAS 95464-05-4). The mixture is stirred for 6 hours at 100° C. and then for 15 hours at 80° C., then cooled to room temperature and filtered through Celite™. The Celite is rinsed with 100 ml of ethyl acetate and 30 ml of water are added to the combined filtrates. The organic phase is separated out by settling, dried over sodium sulfate, filtered and concentrated under reduced pressure. The residue obtained is chromatographed on a column of silica gel, eluting with a mixture of 5 to 50% ethyl acetate in dichloromethane, to give 1.50 g of tert-butyl 8-carbamoyl-6-chloro-7-phenyl-3,4-dihydropyrrolo[1,2-a]pyrazine-2(1H)-carboxylate in the form of a white solid after recrystallization from ethyl acetate and drying at 60° C. under reduced pressure.

Workup

  1. waitfor 15 hours at 80° C.
  2. temperaturecooled to room temperature
  3. filtrationfiltered through Celite™
  4. washThe Celite is rinsed with 100 ml of ethyl acetate and 30 ml of water
  5. additionare added to the combined filtrates
  6. customThe organic phase is separated out
  7. dry with materialdried over sodium sulfate
  8. filtrationfiltered
  9. concentrationconcentrated under reduced pressure
  10. customThe residue obtained
  11. customis chromatographed on a column of silica gel
  12. washeluting with a mixture of 5 to 50% ethyl acetate in dichloromethane

Sources & evidence

ORD record
ord-7e73940321684439b081536750c4cfe1
Source dataset
uspto-grants-2014_07
Patent number
US08791119B2

Reaction notes

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