Hydrochloric Acid → [1,2,4]Triazolo[1,5-a]pyridine-7-carboxylic acid

To a solution of methyl 2-aminoisonicotinate (28.8 g, 191 mmol) in DMF (97.5 mL) was added DMF-DMA (70.6 mL, 496 mmol) and the mixture heated to 130° C. for 12 hours. The mixture was then concentrated to give a residue. To the residue was added methanol (381 mL), followed by NH2OHSO4 (31.9 g, 248 mmol) and the resulting mixture was stirred at room temperature overnight. The reaction mixture was concentrated to give methyl[1,2,4]triazolo[1,5-a]pyridine-7-carboxylate in 18% yield, 6 g. To a solution of methyl[1,2,4]triazolo[1,5-a]pyridine-7-carboxylate (3 g, 16 mmol) in methanol was added 1M aq. LiOH (70 mL) and the resulting mixture stirred for 10 hours at room temperature. The pH was adjusted to 5-6 using aq. HCl and the whole mixture extracted with EtOAc (30 mL×3). The combined organic layers were dried over Na2SO4 and concentrated in vacuo to give the title compound as white solid in 38% yield, 1.05 g 1H NMR (400 MHz, DMSO-d6): δ13.5-14.0 (s, 1H), 9.04-9.06 (m, 1H), 8.66 (m, 1H), 8.32 (m, 1H), 67.56-7.58 (m, 1H).

1. extractionthe whole mixture extracted with EtOAc (30 mL×3)
2. dry with materialThe combined organic layers were dried over Na2SO4
3. concentrationconcentrated in vacuo

ORD-Eintrag

ord-a61c4c8ac902432ab6416e8b62bfc7de

Quelldatensatz

uspto-grants-2014_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08846698B2