反应详情

A mixture of 3-aminomethyl-2-thienylacetic acid 8 (3.1 g, 18 m. moles) and triethylamine (8 g. 80 m moles) in 50% aqueous acetone (80 ml) was added dropwise t-butoxycarbonyl azide (5.7 g, 40 m moles) over a period of 20 mins. at 0° C. with vigorous stirring. The reaction mixture was stirred overnight at room temperature and concentrated under reduced pressure. The concentrate was washed with ether (2×20 ml), adjusted to pH 2 with conc. HCl and extracted with ethyl acetate (2×50 ml). The ethyl acetate extracts were washed with saturated aqueous sodium chloride, dried over MgSO4, treated with charcoal and evaporated under reduced pressure. The residue was triturated with n-hexane and crystallized from n-hexane and benzene to give 4.5 g (92%) of colorless needles 9, melting at 62°-63° C.

1. customat 0° C.
2. concentrationconcentrated under reduced pressure
3. washThe concentrate was washed with ether (2×20 ml)
4. extractionextracted with ethyl acetate (2×50 ml)
5. washThe ethyl acetate extracts were washed with saturated aqueous sodium chloride
6. dry with materialdried over MgSO4
7. additiontreated with charcoal
8. customevaporated under reduced pressure
9. customThe residue was triturated with n-hexane
10. customcrystallized from n-hexane and benzene