Water → HCID 12208471, compound

Participants

Reaction Steps

A solution of O-mesitylenesulfonylhydroxylamine, ˜30-35% water, (14.5 g, 52 mmol) and CH2Cl2 (100 mL) is added to a solution of 3-aminopyridine (4.9 g, 52 mmol) and CH2Cl2 (100 mL) at 0° C. dropwise over 30 min. After 30 min at 0° C., the ice bath is removed and the solution is stirred at rt for 30 min. The volatiles are removed under reduced pressure to afford a yellow oil, N-amino-3-aminopyridinium mesityl sulfonate. DMF (100 mL) and K2CO3 (15 g, 110 mmol) are added. The dark brown mixture is cooled in a water bath. Dimethyl acetylenedicarboxylate (6.9 mL, 56 mmol) are added dropwise over 10 min. After 15 min, the water bath is removed and the mixture is left to vigorously stir under air for 66 h. The volatiles are removed under reduced pressure. The residue is slurried in MeOH and the mixture is filtered through Celite (MeOH rinse). The volatiles are removed under reduced pressure to afford a dark brown oil. 33% Sat. aq. NaHCO3 (150 mL) is added and the solution is extracted with EtOAc (6×200 mL). The combined organics are dried over Na2SO4, filtered, and concentrated. Purification by flash column chromatography (CH2Cl2) affords the title compound as an orange-red oil. LC-MS m/z (M+Na+): 272.01.

Provenance & Evidence