反应详情

To a solution of 3.06 g of 2-amino-4,5-dimethylthiophenol in 50 ml of dimethylformamide was added 5.48 g of methyl 2,5-dibromovalerate at room temperature with stirring. The mixture was stirred for 14 hours, poured into water, and extracted with ethyl acetate. The ethyl acetate layer was washed with water, dried (MgSO4), and concentrated. The residue was washed with a mixture of ether and hexane to obtain 4.35 g (69.3%) of 2-(3-bromopropyl)-6,7-dimethyl-2H-1,4-benzothiazin-3(4H)-one as crystals. Recrystallization from methanol gave prisms, m.p. 151°-153° C.

1. stirringThe mixture was stirred for 14 hours
2. extractionextracted with ethyl acetate
3. washThe ethyl acetate layer was washed with water
4. dry with materialdried (MgSO4)
5. concentrationconcentrated
6. washThe residue was washed with a mixture of ether and hexane