Butanedione → 4,9-Dibromo-6,7-dimethyl-[1,2,5]thiadiazolo[3,4-g]quinoxaline

HRID 1176157Notes

Reaction equation

HRID 1176157 reaction equation
[NH2:1][C:2]1[C:10]([NH2:11])=[C:9]([Br:12])[C:5]2=[N:6][S:7][N:8]=[C:4]2[C:3]=1[Br:13].[CH3:14][C:15](=O)[C:16](=O)[CH3:17].O>C(O)(=O)C>[Br:13][C:3]1[C:4]2[C:5](=[N:6][S:7][N:8]=2)[C:9]([Br:12])=[C:10]2[C:2]=1[N:1]=[C:16]([CH3:17])[C:15]([CH3:14])=[N:11]2

Participants

5

Reactant 3

HCID 650ButanedioneHCID 962WaterHCID 684083434,7-Dibromo-2,1,3-benzothiadiazole-5,6-diamine

Product 1

HCID 684083444,9-Dibromo-6,7-dimethyl-[1,2,5]thiadiazolo[3,4-g]quinoxaline

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

5,6-Diamino-4,7-dibromobenzo[c][1,2,5]thiadiazole (0.257 g, 7.93×10−4 mol) was dissolved in acetic acid (30 ml). 2,3-Butanedione (0.30 ml, 3.4×10−3 mol) was added, and the reaction mixture was stirred for 19 h at room temperature under N2. Water (50 ml) was added, and the resulting precipitate was filtered, dissolved in CH2Cl2, washed with water, and dried over Na2SO4. After the solvent was evaporated, the residue was chromatographed on silica gel with CHCl3. Yield=0.256 g (86% based on 0.257 g of 5,6-diamino-4,7-dibromobenzo[c][1,2,5]thiadiazole). 1H NMR (360 MHz, CDCl3): δ 2.88 (s, 6H, —CH3). Chemical Ionization MS m/z: 371.8675 (M+) (calcd 371.868).

Workup

  1. filtrationthe resulting precipitate was filtered
  2. dissolutiondissolved in CH2Cl2
  3. washwashed with water
  4. dry with materialdried over Na2SO4
  5. customAfter the solvent was evaporated
  6. customthe residue was chromatographed on silica gel with CHCl3

Sources & evidence

ORD record
ord-85717c072ea944ec9c9f57e780545a43
Source dataset
uspto-grants-2010_11
Patent number
US07842758B2

Reaction notes

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