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-153749973c1a4feb9d9011d8cc679c1e

Source dataset

uspto-grants-2016_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09249162B2