[C:1](O)(=O)[C:2]([CH3:5])([CH3:4])[CH3:3].[C:8]([C:10]1[CH:11]=[N:12]C=[CH:14][CH:15]=1)#[N:9].OS(O)(=O)=O.[OH-].[Na+]>O.[N+]([O-])([O-])=O.[Ag+]>[C:2]([C:1]1[CH:14]=[CH:15][C:10]([C:11]#[N:12])=[CH:8][N:9]=1)([CH3:5])([CH3:4])[CH3:3]Pivalic acid (144 mol, 5 eq) and AgNO3 (3.76 mmol, 0.13 eq) are added to a suspension of the 3-cyanopyridine (29 mmol, 1 eq) in 40 ml H2O. The mixture is stirred for 20 min after which is added 60 ml of a 10% H2SO4 solution. The reaction is stirred for a further 20 min then heated to 70° C. An aqueous solution of (NH4)2S2O8 (8.6 mmol, 1.3 eq) is added dropwise over 30 minutes and the heating is continued for 2 hours or until completion by TLC. After cooling the in ice, 2 N NaOH is added and the reaction is extracted 3 times with ethyl acetate, dried over Na2SO4, filtered and concentration. Purification is performed on silica gel with ethyl acetate/hexanes.
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