3-Methyl-isothiazole → 5-(5-Chloropentyl)-3-methylisothiazole

HRID 2165438Notes

Reaction equation

HRID 2165438 reaction equation
[CH3:1][C:2]1[CH:6]=[CH:5][S:4][N:3]=1.C([Li])CCC.Br[CH2:13][CH2:14][CH2:15][CH2:16][CH2:17][Cl:18]>O1CCCC1.CCOCC>[Cl:18][CH2:17][CH2:16][CH2:15][CH2:14][CH2:13][C:5]1[S:4][N:3]=[C:2]([CH3:1])[CH:6]=1

Participants

6

Reactant 3

HCID 127473-Methyl-isothiazoleHCID 960701-Bromo-5-chloropentaneHCID 178418339Butyllithium

Product 1

HCID 200639705-(5-Chloropentyl)-3-methylisothiazoleYield 49.4%

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolvent2×HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 6.4 g 3-methylisothiazole in 100 ml dry tetrahydrofuran at -78° C. under nitrogen was slowly added 7.6 ml n-butyllithium (9.5 m). After 15 min. at -78° C., a solution of 12.0 g 1-bromo-5-chloropentane in 10 ml dry ether was added. The reaction mixture was allowed to reach room temperature where it was stirred for 90 min., then diluted with ether, washed with water and sodium chloride solution, and dried over sodium sulfate. Concentration and flash filtration (silica gel, 4:1 hexane/ethyl acetate) gave 6.5 g of 5-(5-chloropentyl)-3-methylisothiazole as a red oil, sufficiently pure (NMR) for use in the subsequent reaction.

Workup

  1. customat -78° C.
  2. customto reach room temperature
  3. washwashed with water and sodium chloride solution
  4. dry with materialdried over sodium sulfate
  5. concentrationConcentration and flash filtration (silica gel, 4:1 hexane/ethyl acetate)

Sources & evidence

ORD record
ord-bedb97a558e74664b101bea7b21f55e3
Source dataset
uspto-grants-1990_07
Patent number
US04939267

Reaction notes

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