Bromide ion → 4-(1-(4-(trifluoromethoxy)phenyl)-1H-1,2,4-triazol-3-yl)aniline

Temperature

-20 °C

1-(4-Trifluoromethoxyphenyl)-3-(4-nitrophenyl)-1H-[1,2,4]triazole. A solution of NBS (0.70 g, 3.9 mmol) in 25 mL of CH2Cl2 was stirred under nitrogen at 0° C. while dimethyl sulfide (0.40 g, 6.5 mmol) was added via syringe. The solution, which forms a white solid, was then cooled to −20° C., and N-(4-nitrobenzylidene)-N′-(4-trifluoromethoxyphenyl)-hydrazine (0.70 g, 2.15 mmol) in 10 mL of DCM was added. The solution was allowed to warm to ambient temperature and stirred an additional 2 h. The resulting orange solution was then diluted with 25 mL of DCM and washed with water and brine before drying and concentrating. The resulting orange solid hydrazonyl bromide (0.9 g) was then treated directly with tetrazole (154 mg, 2.2 mmol) and triethylamine (280 μL, 0.23 mmol) in 5 mL of absolute EtOH. The resulting orange-brown solution was heated at reflux for 2 h. TLC showed that the initial bromide was first converted into two yellow intermediates, which were replaced by a single, colorless, spot. The orange solution was then concentrated and purified by chromatography (2:1:2 Hexane/EtOAc/DCM), yielding 0.30 g of the title compound as a light yellow solid. 1H NMR (300 MHz, CDCl3) δ 8.68 (s, 1H), 8.40 (d, J=5 Hz, 2H), 8.35 (d, J=5 Hz, 2H), 7.85 (d, J=8 Hz, 2H), 7.42 (d, J=8 Hz, 2H); EIMS 350 (M+, 100), 299 (57); mp 147° C.

1. additionwas added via syringe
2. temperatureto warm to ambient temperature
3. washwashed with water and brine
4. custombefore drying
5. concentrationconcentrating
6. temperatureThe resulting orange-brown solution was heated
7. temperatureat reflux for 2 h
8. concentrationThe orange solution was then concentrated
9. custompurified by chromatography (2:1:2 Hexane/EtOAc/DCM)

ORD record

ord-0506d762e07942d5906180f84ea70b23

Source dataset

uspto-grants-2012_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08178658B2