Cyclohexanecarbonyl chloride → 2-Cyclohexyl-5-(4-nitro-phenyl)-[1,3,4]oxadiazole

A mixture of 5-(4-nitro-phenyl)-1H-tetrazole (0.5 g, 2.62 mmol) and cyclohexane carbonyl chloride (0.35 ml, 2.62 mmol) in 3 ml anhydrous pyridine was stirred at room temperature under nitrogen for 20 min, then heated to 60° C. for 1 hr and finally heated to 100° C. for 2 h. The reaction mixture was cooled to room temperature then poured onto ice (30 g) and the aqueous mixture was extracted with 30 ml ethyl acetate. The ethyl acetate solution was washed sequentially with 30 ml water, 30 ml 1N aqueous hydrochloric acid solution and 30 ml brine, dried (anhydrous sodium sulfate) and concentrated under reduced pressure. The crude produce was purified by flash column chromatography (silica gel, 40 g), eluting with 4:1 hexane/ethyl acetate to yield the title compound as a yellowish solid (0.5 g, 100% yield). MS: 274.2 (M+1)

1. temperatureheated to 60° C. for 1 hr
2. temperaturefinally heated to 100° C. for 2 h
3. temperatureThe reaction mixture was cooled to room temperature
4. additionthen poured onto ice (30 g)
5. extractionthe aqueous mixture was extracted with 30 ml ethyl acetate
6. washThe ethyl acetate solution was washed sequentially with 30 ml water, 30 ml 1N aqueous hydrochloric acid solution and 30 ml brine
7. dry with materialdried (anhydrous sodium sulfate)
8. concentrationconcentrated under reduced pressure
9. customThe crude produce
10. customwas purified by flash column chromatography (silica gel, 40 g)
11. washeluting with 4:1 hexane/ethyl acetate

ORD record

ord-069b4fcdc9e2489fb2861fae16206106

Source dataset

uspto-grants-2007_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07262318B2