Toluene → isopropyl 7-bromo-3-oxo-3,4-dihydroquinoxaline-1(2H)-carboxylate

HRID 2230061Notes

Reaction equation

HRID 2230061 reaction equation
[Br:1][C:2]1[CH:11]=[C:10]2[C:5]([NH:6][C:7](=[O:12])[CH:8]=[N:9]2)=[CH:4][CH:3]=1.Cl[C:14]([O:16][CH:17]([CH3:19])[CH3:18])=[O:15].C1(C)C=CC=CC=1>N1C=CC=CC=1>[Br:1][C:2]1[CH:11]=[C:10]2[C:5]([NH:6][C:7](=[O:12])[CH2:8][N:9]2[C:14]([O:16][CH:17]([CH3:19])[CH3:18])=[O:15])=[CH:4][CH:3]=1

Participants

5

Reactant 3

HCID 1140TolueneHCID 7917Isopropyl chloroformateHCID 126863946-Bromo-1,2-dihydroquinoxalin-2-one

Product 1

HCID 18464405isopropyl 7-bromo-3-oxo-3,4-dihydroquinoxaline-1(2H)-carboxylateYield 97%

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

To a solution of 7-bromo-3-oxo-3,4-dihydroquinoxaline (6.8 g, 30 mmol) in pyridine (50 ml) was added a solution of isopropyl chloroformate in toluene (35 ml, 1M, 35 mmol) over 30 minutes. The mixture was triturated with water/chloroform, the organic layer was separated, washed with brine, dried over magnesium sulfate, and evaporated to obtain crude isopropyl 7-bromo-3-oxo-3,4-dihydroquinoxaline-1(2H)-carboxylate (9.3 g, 97%). A sample was recrystallized from ethanol: m p. 159-161° C. 1H-NMR (DMSO-d6) δ 1.25 (d, J=6.2 Hz, 6H), 4.25 (s, 2H), 4.90 (sep, J=6.2 Hz, 1H), 6.89 (d,J=8.6 Hz, 1H), 7.27 (dd,J=9.1, 2.1 Hz, 1H), 7.74(s, 1H), 12.51 (s, 1H), MS (ESI) m/z 330/332 (M+NH4)+.

Workup

  1. customThe mixture was triturated with water/chloroform
  2. customthe organic layer was separated
  3. washwashed with brine
  4. dry with materialdried over magnesium sulfate
  5. customevaporated

Sources & evidence

ORD record
ord-2ea69550869f4b5da88774a671433f9c
Source dataset
uspto-grants-2002_07
Patent number
US06423699B1

Reaction notes

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