Toluene → isopropyl 7-bromo-3-oxo-3,4-dihydroquinoxaline-1(2H)-carboxylate
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]=1Participants
5
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: mp. 159-161° C.
Workup
- customThe mixture was triturated with water/chloroform
- customthe organic layer was separated
- washwashed with brine
- dry with materialdried over magnesium sulfate
- customevaporated
Sources & evidence
- ORD record
- ord-e4611b4b7c6f4078984f03df1d28a66c
- Source dataset
- uspto-grants-2002_04
- Patent number
- US06380235B1
Reaction notes
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