C([O:3][C:4]([C:6]1[N:14]=[C:9]2[CH:10]=[CH:11][CH:12]=[CH:13][N:8]2[N:7]=1)=O)C.C1COCC1.[BH4-].[Na+].[NH4+].[Cl-]>ClCCl.O.C(O)C>[N:14]1[C:6]([CH2:4][OH:3])=[N:7][N:8]2[CH:13]=[CH:12][CH:11]=[CH:10][C:9]=12
Under argon atmosphere, ethyl[1,2,4]triazolo[1,5-a]pyridine-2-carboxylate (1 g, 5.23 mmol) was combined with THF (10 mL) at RT to give a brown suspension. Sodium borohydride (1.19 g, 31.4 mmol) was added in four portions. The mixture was heated to 65° C. for 15 min. After cooling down to RT, ethanol (10 mL) was added dropwise over a period of 15 min. The mixture was stirred at 65° C. for 4 h. The mixture was cooled down to 0-5° C. and NH4Cl (saturated aqueous solution, 20 mL) was added dropwise over a period of 10 min (foam!). Water (20 mL) was added and the yellow suspension was poured into dichloromethane (100 mL) and extracted with dichloromethane (4×75 mL). The combined organic layer was dried over MgSO4 and concentrated in vacuo to give the product as light yellow solid (720 mg, 4.76 mmol, 91%) which was used without further purification for the next step.
Wird geladen…
