N-bromobutanimide → 3-Bromo-4-chloro-2,3-dihydro-2,2-dimethyl-7-nitrobenzofuran

Participants

Reaction Steps

A mixture of 11.82 g (0.052 mole) of 4-chloro-2,3-dihydro-2,2-dimethyl-7-nitrobenzofuran (Example 1, Step C) and 9.3 g (0.052 mole) of N-bromosuccinimide in 200 mL of carbon tetrachloride was irradiated with a sun lamp for approximately 16 hours. No reaction occurred during this time. To this mixture was then added 0.10 g of benzoyl peroxide, and the reaction mixture was then heated at reflux and irradiated simultaneously for a period of five hours. The sun lamp was turned off, and the mixture was allowed to stir while being heated at reflux for an additional hour. The mixture was then passed through a column of silica gel, and product-containing fractions were combined. The solvent was evaporated from the combined fractions under reduced pressure, leaving 15.2 g of 3-bromo-4-chloro-2,3-dihydro-2,2-dimethyl-7-nitrobenzofuran as a solid, m.p. 103°-104° C.

Provenance & Evidence