2-Amino-3-pyridinecarboxaldehyde

yellow crystals

Crude 2-(pivaloylamino)-3-pyridinecarboxaldehyde (from step b, 43 g) was dissolved in 3 M HCl (500 mL), and the solution was heated to reflux. After 18 hr the mixture was cooled to RT, and the pH was carefully adjusted to 7 using solid K2CO3. The aqueous solution was extracted with EtOAc (3 x 500 mL). The combined organic layers were dried (MgSO4)and concentrated to give the title compound (24.57 g, 101 percent) as a reddish brown solid: 1H NMR (300 MHz, CDCl3) δ 9.85 (s, 1 H), 8.24 (m, 1 H), 7.80 (m, 1 H), 6.90 (br s, 2 H), 6.74 (m, 2 H); MS (ES) m/e 123 (M + H)+.Preparation Example J-4. To a mixture of (2-aminopyridin-3-yl)-methanol described in Preparation Example J-3 (130mg, 1.1mmol) and dichloromethane (10mL) was added manganese dioxide (1.3g, 15mmol) at room temperature, and the solution was stirred overnight. The reaction solution was filtered through Celite pad, then, the solvent was evaporated in vacuo, and the title compound (108mg, 0.88mmol, 83percent) was obtained as a white solid. The compound was prepared according to the procedure as described by A. E. Moormann et al, Synthetic Communications, 17(14), 1695-1699 (1987) To a solution of 2-[3-(dibromomethyl)-2-pyridinyl]-1H-isoindole-1, 3(2H)-dione (20 g, 50 mmol) in ethanol (250 ml) was added conc. NH4OH (25 ml) at 4° C. The reaction mixture was stirred 10 minutes at 4° C. then stirred at room temperature for one hour. Reaction mixture was concentrated under reduced pressure. To the concentrated residue was added con. HCl (150 ml) and mixture was refluxed for 3 hours. The reaction mixture was cooled to room temperature and concentrated. To the concentrated residue was added water (25 ml) then added saturated K2CO3 to neutralize the solution. The solution was extracted with methylenechloride (3.x.150 ml). Combined organic solution was washed with water (3.x.150 ml), brine (1.x.200 ml), dried over Na2SO4, concentrated. The concentrated residue was suspended in ether, filtered and washed with ether to give 4.3 g (70percent) yellow solid. NMR (DMSO) δ 6.69-6.73 (m, 1H), 7.51 (bs, 2H), 7.95-7.98(m, 1H), 8.20-8.22 (m, 1H), 9.82 (s, 1H).Preparation of 2mol / L HC1 solution. The dried sample was transferred to a 50 mL single-necked flask and then about 30 mL of 2 mol / L HC1 solution was added and the temperature was refluxed for 4 hours and cooled to room temperature. The pH was adjusted to 7 to 8 with 10 mol / L NaOH solution. Ether extraction 5 times, anhydrous potassium carbonate drying, steaming to remove the solvent, a yellow solid. Column chromatography (VD ™ / VEIQH = 30: 1) and dried at low temperature to give pale yellow pure 2-amino-3-pyridinecarboxaldehyde in 30percent yield.To 500mL flask 73g 3- pyridine plus three amide (0.6mol) and 104g of ammonium sulfate (0.9mol), heated to melt, slowly warmed to 200 ° C, the system was gradually solidified reaction incubated 12h. Cooled to room temperature, stirred out of diethyl ether was added 500mL soluble impurities, suction filtration to give crude compound 3. The resulting crude product was added 100mL of concentrated hydrochloric acid was stirred at reflux for 8 hours, the system was adjusted with a sodium hydroxide solution to a neutral PH, and extracted with ether to give crude compound 4, silica gel column chromatography to Vzarii:percent [imitation = 1:20 to wash degreasing agent, to give a pale yellow crystalline powder carbaldehyde 13.8 g of 2-amino-3-pyridyl, yield 18.8percent.

Molecular Weight:122.12
XLogP3:0.5
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:3
Rotatable Bond Count:1
Exact Mass:122.048012819
Monoisotopic Mass:122.048012819
Topological Polar Surface Area:56
Heavy Atom Count:9
Complexity:105
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes