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

Participants

Reaction Steps

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).

Provenance & Evidence