[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([CH2:8][C:9](O)=[O:10])=[CH:4][N:3]=1.C(N(CC)CC)C.ClC(OCC(C)C)=O.[BH4-].[Na+]>C1COCC1>[Cl:1][C:2]1[N:3]=[CH:4][C:5]([CH2:8][CH2:9][OH:10])=[CH:6][CH:7]=1To a stirred solution of 2-chloropyridine-5-acetic acid (800 mg, 4.60 mmol) in THF (30 mL) at 0° C. under a nitrogen atmosphere was added triethylamine (2.20 mL, 10.3 mmol) and isobutyl chloroformate (1.20 mL, 9.33 mmol). The reaction was stirred for 50 minutes then sodium borohydride (1.77 g, 46 mmol) was added and the suspension stirred at r.t. for 16 h then at reflux for a further 4 h. The resulting mixture was partitioned between DCM (50 mL) and water (50 mL). The organic fraction was washed with brine (50 mL), dried (MgSO4) and concentrated in vacuo to yield the title compound (800 mg, quantitative) as a brown oil. LCMS (ES+) 158.0 (M+H)+, RT 1.81 minutes (85% purity) (Method 1).
Wird geladen…