反应详情

15.1 g (0.09 mol) of 6-oxo-2-amino-tetrahydrobenzothiazole and 20.5 g (0.1-mol) of 4-methoxyphenylpropionyl chloride are refluxed for 2 hours in 450 ml of tetrahydrofuran and 0.1 mol of triethylamine, subsequently poured onto ice and extracted with ethyl acetate. After drying, 2-(4-methoxyphenylpropionyl)amino-6-oxo-tetrahydrobenzothiazole (17.5 g) crystallises out on concentrating, and, is dissolved in methanol and is reductively aminated, without further purification, in an autoclave using propylamine (Raney nickel, 5 bar, 60° C.). After filtering off the catalyst under suction, the solvent is removed by distillation. The residue crystallises from i-propyl ether. Yield: 12.5 g (63% of theory)

1. extractionextracted with ethyl acetate
2. customAfter drying
3. custom2-(4-methoxyphenylpropionyl)amino-6-oxo-tetrahydrobenzothiazole (17.5 g) crystallises out
4. concentrationon concentrating
5. dissolutionis dissolved in methanol
6. customis reductively aminated, without further purification, in an autoclave
7. custompropylamine (Raney nickel, 5 bar, 60° C.)
8. filtrationAfter filtering off the catalyst under suction
9. customthe solvent is removed by distillation
10. customThe residue crystallises from i-propyl ether