反应详情

5.0 g (21.3 mmol) of methyl 2-amino-5-phenyl-4-thiazolecarboxylate (which was prepared as described in J. Chem. Soc. Perk. Trans. I (1982) 159-164) and 6.84 g (42.7 mmol) of t-butyl (2-aminoethyl)carbamate were heated under reduced pressure for 2 hours at a bath temperature of 140°, whereby the methanol formed was distilled off continuously. After cooling the residue was dissolved in 50 ml of methylene chloride and chromatographed on 200 g of silica gel with a 9:1 mixture of methylene chloride and methanol as the eluting agent. The fractions which were pure according to the thin-layer chromatogram were combined and evaporated under reduced pressure, whereby there were obtained 4.5 g of a red, crystallizing oil. Crystallization from methanol and an ether/hexane mixture yielded 3.48 g (45%) of t-butyl [2-(2-amino-5-phenyl-4-thiazolecarboxamido)ethyl]carbamate as beige crystals which were used without further purification.

1. customformed
2. distillationwas distilled off continuously
3. temperatureAfter cooling the residue
4. dissolutionwas dissolved in 50 ml of methylene chloride
5. customchromatographed on 200 g of silica gel with a 9:1 mixture of methylene chloride and methanol as the eluting agent
6. customevaporated under reduced pressure
7. customwhereby there were obtained 4.5 g of a red,
8. customcrystallizing oil
9. customCrystallization from methanol