Hydrochloric Acid → (S)-tert-butyl 7-bromo-4-(cyclopropanecarbonyl)-3-methyl-3,4-dihydroquinoxaline-1(2H)-carboxylate

HRID 1485671Notes

Reaction equation

HRID 1485671 reaction equation
[Br:1][C:2]1[CH:11]=[C:10]2[C:5]([NH:6][C@@H:7]([CH3:19])[CH2:8][N:9]2[C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])=[CH:4][CH:3]=1.N1C=CC=CC=1.[CH:26]1([C:29](Cl)=[O:30])[CH2:28][CH2:27]1.Cl>ClCCl>[Br:1][C:2]1[CH:11]=[C:10]2[C:5]([N:6]([C:29]([CH:26]3[CH2:28][CH2:27]3)=[O:30])[C@@H:7]([CH3:19])[CH2:8][N:9]2[C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])=[CH:4][CH:3]=1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 1049PyridineHCID 77637Cyclopropanecarbonyl chlorideHCID 118079280(S)-tert-butyl 7-bromo-3-methyl-3,4-dihydroquinoxaline-1(2H)-carboxylate

Product 1

HCID 118080289(S)-tert-butyl 7-bromo-4-(cyclopropanecarbonyl)-3-methyl-3,4-dihydroquinoxaline-1(2H)-carboxylateYield 99.7%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

A 100-mL round bottomed flask fitted with a nitrogen inlet and magnetic stir bar was charged with (S)-tert-butyl 7-bromo-3-methyl-3,4-dihydroquinoxaline-1(2H)-carboxylate (4.75 g, 14.52 mmol), dichloromethane (50 mL), pyridine (1.996 mL, 24.68 mmol), and cyclopropanecarbonyl chloride (1.976 mL, 21.77 mmol). The reaction mixture was stirred at rt for 2 h and then 1 M aqueous HCl solution (25 mL) was added. The organic layer was separated and concentrated under reduced pressure to afford (S)-tert-butyl 7-bromo-4-(cyclopropanecarbonyl)-3-methyl-3,4-dihydroquinoxaline-1(2H)-carboxylate (5.72 g, 99%) as a solid, which was used directly in next step. MS (ESI, pos. ion) m/z 395, 397 [M+1]+.

Workup

  1. customA 100-mL round bottomed flask fitted with a nitrogen inlet and magnetic stir bar
  2. customThe organic layer was separated
  3. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-5048b777d6594c55b3c5ba5d75f706ae
Source dataset
uspto-grants-2016_08
Patent number
US09422281B2

Reaction notes

Loading…