Methyl iodide → 5-Bromo-2-ethyl-1,3-benzothiazole

HRID 1785762Notes

Reaction equation

HRID 1785762 reaction equation
[CH:1](NC(C)C)(C)C.C([Li])CCC.[Br:13][C:14]1[CH:15]=[CH:16][C:17]2[S:21][C:20]([CH3:22])=[N:19][C:18]=2[CH:23]=1.IC>C1COCC1.C(OCC)(=O)C>[Br:13][C:14]1[CH:15]=[CH:16][C:17]2[S:21][C:20]([CH2:22][CH3:1])=[N:19][C:18]=2[CH:23]=1

Participants

7

Reactant 4

HCID 6328Methyl iodideHCID 7912DiisopropylamineHCID 30174575-Bromo-2-methylbenzothiazoleHCID 178418339Butyllithium

Product 1

HCID 227302205-Bromo-2-ethyl-1,3-benzothiazole

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolvent2×HCID 8857Ethyl AcetateSolvent

Procedure

A 0° C. solution of diisopropylamine (340 μL, 2.41 mmol) in THF (3 mL) was treated with 2.5M n-butyllithium in hexanes (0.88 mL), stirred for 20 minutes, added to a −78° C. solution of 5-bromo-2-methyl-1,3-benzothiazole (250 mg, 1.10 mmol) in THF (3 mL), stirred for 30 minutes, treated with iodomethane (340 μL, 5.50 mmol), and stirred for 1 hour. The mixture was diluted with ethyl acetate (50 mL), washed sequentially with 1M HCl (5 mL), water (5 mL), and brine (5 mL), dried (MgSO4), filtered, and concentrated. The concentrate was purified by flash column chromatography on silica gel with 30% hexanes/dichloromethane to provide the desired product. MS (DCI) m/e 242 (M+H)+.

Workup

  1. stirringstirred for 30 minutes
  2. stirringstirred for 1 hour
  3. washwashed sequentially with 1M HCl (5 mL), water (5 mL), and brine (5 mL)
  4. dry with materialdried (MgSO4)
  5. filtrationfiltered
  6. concentrationconcentrated
  7. customThe concentrate was purified by flash column chromatography on silica gel with 30% hexanes/dichloromethane

Sources & evidence

ORD record
ord-794ece45b1d0482a85885c6158392336
Source dataset
uspto-grants-2009_03
Patent number
US07504512B2

Reaction notes

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