Nitrobenzene → 3-(4-Nitrophenyl)oxacyclopentan-2-one

A solution of 2.75 g (10 mmol) of TASF in 3 mL of acetonitrile and 3 mL of THF was added to a solution of 1.02 mL (10 mmol) of nitrobenzene and 1.93 mL (10.50 mmol) of [(oxacyclopent-2-ene-2-yl)oxy]trimethylsilane (OCS) in 12 mL of anhydrous THF at -78° C. over 10 min. The last traces of TASF from the dropping funnel were washed down with additional 5 mL of THF. The mixture was stirred for 20 hrs. at -78° C. Then, 0.460 mL (8.98 mmol) of bromine was added from a dropping funnel. The mixture was stirred at -78° C. for 15 min, and then the cold bath was removed. Stirring was continued for 1 hr. Thirty mL of freshly prepared saturated sodium bisulfite was added, and the product was extracted into four 60 mL portions of ether. Combined ether extracts were washed with saturated potassium hydrogen phosphate and sodium chloride. Concentration and chromatography on silica yielded two products identified as the ortho and para addition products. The ortho-adduct yielded 0.660 g (32%) of product which had a melting point of 112°-117° C. (dec). The para-adduct yielded 0.282 g (14%) of product which had a melting point of 76° to 78° C. Both the o- and p- products were analyzed by ultraviolet absorption, infrared spectroscopy, nuclear magnetic resonance spectroscopy, and mass spectrometry.

1. washThe last traces of TASF from the dropping funnel were washed down with additional 5 mL of THF
2. customat -78° C
3. stirringThe mixture was stirred at -78° C. for 15 min
4. customthe cold bath was removed
5. stirringStirring
6. waitwas continued for 1 hr
7. additionThirty mL of freshly prepared saturated sodium bisulfite was added
8. extractionthe product was extracted into four 60 mL portions of ether
9. washCombined ether extracts were washed with saturated potassium hydrogen phosphate and sodium chloride
10. concentrationConcentration and chromatography on silica
11. customyielded two products
12. additionidentified as the ortho and para addition products

ORD record

ord-ac7cafb7126d42bd89ea7999db854514

Source dataset

uspto-grants-1990_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04912220