3-Aminopyridine-2-carboxylic acid ethyl ester

A suspension of 3-aminopicolinic acid (1-18) (28 g, 200 mmoL, 1.0 eq) in EtOH (800 mL) at room temperature was bubbled with HCI (g) for 10 min. The reaction turned into a clear yellow solution. After being stirred at 100°C for 1 day, LCMS indicated that about 50percent of starting material remained. The reaction mixture was cooled to rt and bubbled with HCI (g) for 10 min. The mixture was then re-heated to 100 °C. After being stirred at 100 °C for 1 day, LCMS indicated that about 50percent of the starting material remained. The reaction mixture was cooled to rt and all solvents were removed under reduced pressure. The residue was resolved in EtOH (800 mL) and was bubbled with HCI (g) for 10 min. The resulting mixture was refluxed at 100°C oil bath for 1 day. LCMS indicated about 70-75 percent conversion. The reaction mixture was cooled to rt and all solvents were removed under reduced pressure. The solid was dissolved in 250 mL water and the solution was quenched to pH = 8-9 with saturated aq Na2C03. A gas was generated and a white solid formed. The suspension was filtered, washed with water, and dried under vacuum at 65°C to afford 22 g of ethyl 3-aminopicolinate (1-19) in 65percent yleld as a white solid. LCMS (APCI, M+ + 1 ) 167.0; 1H NMR (300 MHz, DMSO-c/6) 8 ppm 7.84 (dd, J = 4.05, 1 .60 Hz, 1 H), 7.23 - 7.30 (m, 1 H), 7.16 - 7.23 (m, 1 H), 6.65 (br. s., 2 H), 4.27 (q, J = 7.10 Hz, 2 H), 1 .30 (t, J = 7.06 Hz, 3 H).

A synthetic intermediate for the synthesis of Kenpaullone derivatives, Cannabinoid receptor ligands, and nociceptive agents.

Molecular Weight:166.18
XLogP3:1.3
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:4
Rotatable Bond Count:3
Exact Mass:166.074227566
Monoisotopic Mass:166.074227566
Topological Polar Surface Area:65.2
Heavy Atom Count:12
Complexity:161
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes