Chloroacetone → 2-Bromo-6-methylimidazo[2,1-b][1,3,4]thiadiazole

HRID 2409527Notes

Reaction equation

HRID 2409527 reaction equation
[Br:1][C:2]1[S:6][C:5]([NH2:7])=[N:4][N:3]=1.Cl[CH2:9][C:10](=O)[CH3:11].C([O-])(O)=O.[Na+]>O>[Br:1][C:2]1[S:6][C:5]2=[N:7][C:10]([CH3:11])=[CH:9][N:4]2[N:3]=1

Participants

5

Reactant 3

HCID 6571Chloroacetone2×HCID 516892Sodium BicarbonateHCID 36508832-Amino-5-bromo-1,3,4-thiadiazole

Product 1

HCID 153575782-Bromo-6-methylimidazo[2,1-b][1,3,4]thiadiazoleYield 50.6%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

5-bromo-1,3,4-thiadiazol-2-amine (1 g, 5.55 mmol, 1 eq) and chloroacetone (1.327 mL, 16.665 mmol, 3 eq) in water (24 mL) was stirred at reflux temperature overnight. More chloroacetone (1.106 mL, 13.887 mmol, 2.5 eq) was added, and heating was continued over the weekend. The reaction mixture was cooled to RT, poured into NaHCO3 (sat. sol., 43 mL) and extracted with DCM. The organic extracts were dried (MgSO4), filtered and concentrated to give a dark brown residue that was purified by flash chromatography (SiO2, DCM) affording the desired product (white solid, 0.613 g, 50%). HPLC-MS (10-95% B in 4 min at 0.5 mL+2 min 100% B, flow 0.7 mL/min): tR=4.81 min, [M+H]+ m/z 217.9; 1H NMR (300 MHz, CDCl3) δ 7.47 (s, 1H), 2.32 (s, 3H).

Workup

  1. temperatureat reflux temperature overnight
  2. temperatureheating
  3. extractionextracted with DCM
  4. dry with materialThe organic extracts were dried (MgSO4)
  5. filtrationfiltered
  6. concentrationconcentrated
  7. customto give a dark brown residue that
  8. customwas purified by flash chromatography (SiO2, DCM)

Sources & evidence

ORD record
ord-33e8d82b12f048d6b28fdd5ae3411503
Source dataset
uspto-grants-2014_08
Patent number
US08815918B2

Reaction notes

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