Glycerol → 1,5-Naphthyridin-2-amine

Temperature

135 °C

A mixture of pyridine-2,5-diamine (5.2 g, 33.9 mmol), glycerol (15.6 g, 169.5 mmol), sodium 3-nitrobenzenesulphonate (15.2 g, 67.8 mmol), sulfuric acid (20 mL) and water (30 mL) was heated to 135° C. and stirred for 16 h. The mixture was cooled to room temperature and then poured into ice/water (150 g). The pH of the mixture was adjusted to ˜9 with saturated aqueous NaOH solution. Then the mixture was extracted with EtOAc (3×100 mL) and the combined organic layers were dried over anhydrous sodium sulfate and concentrated under reduce pressure to give the crude product, which was purified by silica gel column chromatography (eluting with DCM/MeOH v/v 20:1) to afford the product as a yellow solid (2.0 g, yield 41%). ESI MS: m/z 146 [M+H]+. 1H NMR (400 MHz, DMSO-d6): δ 8.50 (dd, J=1.6 Hz, 4.4 Hz, 1H), 7.94 (d, J=8.8 Hz, 1H), 7.82-7.80 (m, 1H), 7.47 (dd, J=4.0 Hz, 8.4 Hz, 1H), 7.00 (d, J=9.2 Hz, 1H), 6.72 (s, 2H).

1. temperatureThe mixture was cooled to room temperature
2. extractionThen the mixture was extracted with EtOAc (3×100 mL)
3. dry with materialthe combined organic layers were dried over anhydrous sodium sulfate
4. concentrationconcentrated
5. customto give the crude product, which
6. customwas purified by silica gel column chromatography (
7. washeluting with DCM/MeOH v/v 20:1)

ORD record

ord-73619f389e794c748bb0864f21ba32d3

Source dataset

uspto-grants-2014_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08765760B2