2(3H)-Benzothiazolone, 3-methyl- → 5-(2-Bromobutanoyl)-3-methyl-1,3-benzothiazol-2(3H)-one

HRID 1731323Notes

Reaction equation

HRID 1731323 reaction equation
[Cl-].[Al+3].[Cl-].[Cl-].[Br:5][CH:6]([CH2:10][CH3:11])[C:7](Br)=[O:8].[CH3:12][N:13]1[C:17]2[CH:18]=[CH:19][CH:20]=[CH:21][C:16]=2[S:15][C:14]1=[O:22]>C(=S)=S>[Br:5][CH:6]([CH2:10][CH3:11])[C:7]([C:19]1[CH:20]=[CH:21][C:16]2[S:15][C:14](=[O:22])[N:13]([CH3:12])[C:17]=2[CH:18]=1)=[O:8]

Participants

5

Reactant 3

HCID 760312(3H)-Benzothiazolone, 3-methyl-HCID 1172932-Bromobutanoyl bromideHCID 6451240Aluminum(III) Chloride

Product 1

HCID 202287085-(2-Bromobutanoyl)-3-methyl-1,3-benzothiazol-2(3H)-oneYield 62.1%

Reagents, catalysts & solvents 1

HCID 6348Carbon DisulfideSolvent

Procedure

A mixture of aluminum chloride (120 g) and 2-bromobutyryl bromide (48 g) in carbon disulfide (120 ml) was stirred for 30 minutes at ambient temperature. To the resultant mixture was added 3-methyl-2-benzothiazolinone (23 g) and the mixture was stirred for an hour at ambient temperature. The solvent was removed by evaporation at 60°-70° C. and stirred for an hour under the same condition. The reaction mixture was poured into ice-water (360 g) and extracted with chloroform (100 ml×2). The extract was washed with water and dried over magnesium sulfate. The solvent was evaporated in vacuo and the residue was subjected to column chromatography on silica gel (300 g) by eluting with benzene. The fractions containing the desired compound were combined and the solvent was removed by distillation to give 5-(2-bromobutyryl)-3-methyl-2-benzothiazolinone (27.18 g).

Workup

  1. stirringthe mixture was stirred for an hour at ambient temperature
  2. customThe solvent was removed by evaporation at 60°-70° C.
  3. stirringstirred for an hour under the same condition
  4. additionThe reaction mixture was poured into ice-water (360 g)
  5. extractionextracted with chloroform (100 ml×2)
  6. washThe extract was washed with water
  7. dry with materialdried over magnesium sulfate
  8. customThe solvent was evaporated in vacuo
  9. washby eluting with benzene
  10. additionThe fractions containing the desired compound
  11. customthe solvent was removed by distillation

Sources & evidence

ORD record
ord-125f5154a2924b92b7a132428a0514bf
Source dataset
uspto-grants-1986_11
Patent number
US04621084

Reaction notes

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