Nitric Acid → 7-tert-Butyl-2,3-dihydro-3,3-dimethyl-5-nitro-benzofuran

Participants

Reaction Conditions

Reaction Steps

To a solution of 7-tert-butyl-2,3-dihydro-3,3-dimethylbenzofuran (10.0 g 49.0 mmol) in glacial acetic acid (80 mL) is added dropwise 70% HNO3 (4.0 mL, 5.7 g, 63.7 mmol). The reaction mixture darkens to a deep green color over the course of the addition. The reaction is monitored by TLC (2% EtOAc/hexanes), and is allowed to stir at 22° C. for 4 h. Then the reaction mixture is partitioned between Et2O (100 mL) and H2O (2×100 mL). The ethereal layer was washed with saturated aqueous Na2CO3 (50 mL), dried (MgSO4), filtered and evaporated to a red solid (9.12 g). Crystallization from hexane provides the title compound as orange prisms (2.26 g, 18.5%). A second crop yields slightly less pure material (4.93 g, 40.3%) which was used without further purification, mp=93°-94° C.

Provenance & Evidence