Dimethyl Sulfoxide → 2-(3-chloro-1H-1,2,4-triazol-1-yl)-5-nitrophenol

Temperature

100 °C

Step E (1): A mixture of 3-chloro-1H-1,2,4-triazole (2.76 g, 26.7 mmol), 1-chloro-2-methoxy-4-nitrobenzene (5.0 g, 26.7 mmol), potassium hydroxide flakes (1.496 g, 26.7 mmol), and DMSO (25 mL) was heated in a sealed reaction vessel 100° C. for 24 h. The reaction was allowed to cool to rt and additional portions of 3-chloro-1H-1,2,4-triazole (1.38 g, 0.5 equiv) and potassium hydroxide (0.75 g, 0.5 equiv) were added. The reaction vessel was resealed and heated to 110° C. for an additional 24 h. The resulting mixture was allowed to cool to rt and was poured into 500 mL of water. The aqueous mixture was extracted with EtOAc (3×100 mL). The combined organics were washed with brine, dried over Na2SO4, filtered and concentrated in vacuo. The crude residue was purified using silica gel chromatography (0-5% MeOH/chloroform, linear gradient over 144 min, flow 25 mL/min) to afford 2-(3-chloro-1H-1,2,4-triazol-1-yl)-5-nitrophenol (0.924 g, 3.84 mmol, 14.4% yield). LC-MS (M+H)+=241.0. 1H NMR (500 MHz, chloroform-d) δ ppm 11.97 (br. s., 1 H) 9.24 (s, 1 H) 7.90-7.95 (m, 1 H) 7.89 (d, J=2.44 Hz, 1 H) 7.84 (dd, J=8.85, 2.44 Hz, 1 H).

1. temperatureto cool to rt
2. temperatureheated to 110° C. for an additional 24 h
3. temperatureto cool to rt
4. extractionThe aqueous mixture was extracted with EtOAc (3×100 mL)
5. washThe combined organics were washed with brine
6. dry with materialdried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated in vacuo
9. customThe crude residue was purified
10. customsilica gel chromatography (0-5% MeOH/chloroform, linear gradient over 144 min, flow 25 mL/min)

ORD record

ord-463f3f73243040e4a1ce4bc1a4b14d32

Source dataset

uspto-grants-2013_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08349880B2