反应详情

5-Chloro-1H-indole-2-carbaldehyde (0.15 g, 0.76 mmol), NaCNBH3 (0.040 g, 0.63 mmol) and Et3N (0.088 mL, 0.63 mmol) was added to a stirred solution of 3-amino-1H-pyrrole-2-carboxylic acid ethyl ester hydrochloride (0.12 g, 0.63 mmol) in methanol (3 mL). The resulting mixture was stirred at r.t. overnight. The reaction mixture was heated to 50° C. Additional NaCNBH3 (0.5 equiv.) was added and the mixture was stirred at 50° C. for 3 h. A few drops of HOAc was added, and after 1 h the reaction mixture was cooled to r.t. and was concentrated in vacuo. The residue was dissolved in CH2Cl2 (2 mL) and methanol (2 mL). Benzoyl isothiocyanate (0.093 mL, 0.69 mmol) was added and after stirring at r.t. for 1 h the mixture was concentrated in vacuo. The residue was dissolved in ammonia (7N in methanol, 3 mL) and heated at 80° C. for 2 h. The precipitated product was filtered and washed through with methanol and diethyl ether, followed by purification by preparative HPLC, obtaining 0.063 g (30%) of the title compound as a solid.

1. temperatureThe reaction mixture was heated to 50° C
2. stirringthe mixture was stirred at 50° C. for 3 h
3. temperatureafter 1 h the reaction mixture was cooled to r.t.
4. concentrationwas concentrated in vacuo
5. dissolutionThe residue was dissolved in CH2Cl2 (2 mL)
6. stirringafter stirring at r.t. for 1 h the mixture
7. concentrationwas concentrated in vacuo
8. dissolutionThe residue was dissolved in ammonia (7N in methanol, 3 mL)
9. temperatureheated at 80° C. for 2 h
10. filtrationThe precipitated product was filtered
11. washwashed through with methanol and diethyl ether
12. customfollowed by purification by preparative HPLC