Dimethylformamide → Nik 228

HRID 1073207Notes

Reaction equation

HRID 1073207 reaction equation
[CH3:1][C:2]1[N:3]=[C:4]2[N:8]([CH:9]=1)[C:7]1[CH:10]=[CH:11][CH:12]=[CH:13][C:6]=1[S:5]2.CN(C)[CH:16]=[O:17].P(Cl)(Cl)(Cl)=O.[OH-].[NH4+]>O>[CH3:1][C:2]1[N:3]=[C:4]2[N:8]([C:9]=1[CH2:16][OH:17])[C:7]1[CH:10]=[CH:11][CH:12]=[CH:13][C:6]=1[S:5]2

Participants

6

Reactant 4

HCID 6228DimethylformamideHCID 14923Ammonium HydroxideHCID 24813Phosphorus oxychlorideHCID 336507NSC351165

Product 1

HCID 130922Nik 228

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
60 °C

Procedure

In 100 ml of n-butanol were heated 30.0 g of 2-aminobenzothiazole and 25.0 g of propargyl bromide at 100° C. for 6 hours. After cooling, the precipitated crystals were taken out by filtration and recrystallized from water to give 40.0 g of the intermediate. Next, the intermediate was added to 250 ml of sodium ethoxideethanol solution (Na, 3.3 g). The mixture was heated under reflux for one hour. After completion of the reaction, the solvent was removed and water was added to the residue. The precipitated crystals were taken out by filtration to give 22.4 g of 2-methylimidazo[2,1-b]benzothiazole. The benzothiazole was added to a mixture of 300 ml of dry dimethylformamide and 30.0 ml of phosphorus oxychloride followed by heating at 60° C. for 6 hours. After completion of the reaction, the reaction mixture was poured onto 1 liter of chilled water and then was neutralized with ammonium hydroxide. Then, the precipitated crystals were taken out by filtration. The thus obtained formyl compound, 20.5 g, was suspended in 300 ml of methanol and 1.5 g of sodium borohydride was added to the suspension followed by stirring at room temperature for 2 hours. After methanol was removed, the residue was treated with 200 ml of water and filtered to give 20.0 g of the title compound.

Workup

  1. customAfter completion of the reaction
  2. filtrationThen, the precipitated crystals were taken out by filtration
  3. addition1.5 g of sodium borohydride was added to the suspension
  4. customAfter methanol was removed
  5. additionthe residue was treated with 200 ml of water
  6. filtrationfiltered

Sources & evidence

ORD record
ord-6929863599df4e5fb81dc2e24b9ea802
Source dataset
uspto-grants-1990_11
Patent number
US04968708

Reaction notes

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