Propargyl bromide → 2-(N-methyl-N-propynylamino)benzothiazole

HRID 485041

Reaction equation

HRID 485041 reaction equation
[CH3:1][NH:2][C:3]1[S:4][C:5]2[CH:11]=[CH:10][CH:9]=[CH:8][C:6]=2[N:7]=1.[CH3:12][CH2:13][CH2:14]CCC.C([Li])CCC.C(Br)C#C>O1CCCC1.C(Cl)(Cl)Cl>[CH3:1][N:2]([C:3]1[S:4][C:5]2[CH:11]=[CH:10][CH:9]=[CH:8][C:6]=2[N:7]=1)[C:12]#[C:13][CH3:14]

Participants

7

Reactant 4

HCID 7842Propargyl bromideHCID 8058HexaneHCID 28160N-Methylbenzothiazol-2-amineHCID 178418339Butyllithium

Product 1

HCID 202713332-(N-methyl-N-propynylamino)benzothiazoleYield 84%

Reagents, catalysts & solvents 2

HCID 6212ChloroformSolventHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
-78 °C

Procedure

2-Methylaminobenzothiazole (c) (14.0 g) was dissolved in anhydrous tetrahydrofuran (250 ml) and a hexane solution (73 ml) of butyl lithium (6.53 g) was added thereto at -78° C. with stirring. The mixture was stirred for 1.5 hours under cooling and 2-propynyl bromide (8.4 ml) was dropwise added thereto. The resultant mixture was allowed to stand at room temperature overnight and then evaporated to remove the solvent. After addition of water, the residue was extracted with ether. The extract was washed with water, dried and evaporated to remove the solvent. The resultant residue was applied to column chromatography on silica gel (280 g) to give 2-(N-methyl-N-propynylamino)benzothiazole (d) (14.5 g, yield 84%) from chloroform eluate.

Workup

  1. stirringThe mixture was stirred for 1.5 hours
  2. temperatureunder cooling
  3. customevaporated
  4. customto remove the solvent
  5. additionAfter addition of water
  6. extractionthe residue was extracted with ether
  7. washThe extract was washed with water
  8. customdried
  9. customevaporated
  10. customto remove the solvent

Sources & evidence

ORD record
ord-655eb8d90eae40d1a7ee035d7ffa7030
Source dataset
uspto-grants-1985_08
Patent number
US04535088

Linked notes

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