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

HRID 1731320Notes

Reaction equation

HRID 1731320 reaction equation
[Cl-].[Al+3].[Cl-].[Cl-].[Br:5][CH:6]([CH3:10])[C:7](Br)=[O:8].[CH3:11][N:12]1[C:16]2[CH:17]=[CH:18][CH:19]=[CH:20][C:15]=2[S:14][C:13]1=[O:21]>C(=S)=S>[Br:5][CH:6]([CH3:10])[C:7]([C:18]1[CH:19]=[CH:20][C:15]2[S:14][C:13](=[O:21])[N:12]([CH3:11])[C:16]=2[CH:17]=1)=[O:8]

Participants

5

Reactant 3

HCID 760312(3H)-Benzothiazolone, 3-methyl-HCID 79047Propanoyl bromide, 2-bromo-HCID 6451240Aluminum(III) Chloride

Product 1

HCID 139361575-(2-Bromopropanoyl)-3-methyl-1,3-benzothiazol-2(3H)-oneYield 73.7%

Reagents, catalysts & solvents 1

HCID 6348Carbon DisulfideSolvent

Procedure

A mixture of aluminum chloride (51.2 g) and 2-bromopropionyl bromide (25 g) in carbon disulfide (100 ml) was stirred at 35° C. to 40° C. for 30 minutes. To the mixture was added 3-methyl-2-benzothiazolinone (12.7 g) and the resulting mixture was stirred at 40° C. to 45° C. for 5 hours. The reaction mixture was poured into ice-water and extracted with ethyl acetate. The extract was washed with brine, dried over magnesium sulfate and evaporated in vacuo to afford a crystalline residue. The residue was washed with diisopropyl ether to give 5-(2-bromopropionyl)-3-methyl-2-benzothiazolinone (17.0 g).

Workup

  1. stirringthe resulting mixture was stirred at 40° C. to 45° C. for 5 hours
  2. extractionextracted with ethyl acetate
  3. washThe extract was washed with brine
  4. dry with materialdried over magnesium sulfate
  5. customevaporated in vacuo
  6. customto afford a crystalline residue
  7. washThe residue was washed with diisopropyl ether

Sources & evidence

ORD record
ord-0ec8a84518f04f058fe32bf2ad900a21
Source dataset
uspto-grants-1986_11
Patent number
US04621084

Reaction notes

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