Hydrochloric Acid → 6-amino-3,4-epoxy-3,4-dihydro-2,2-dimethyl-7-nitro-2H-1-benzopyran

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Reaction Steps

A mixed solution of a 1,4-dioxane (152 mL) and water (76 mL) in which a 6-acetoamido-3,4-epoxy-3,4-dihydro-2,2-dimethyl-7-nitro-2H-1-benzopyran (synthesized according to the method of Evans, J. M., et al., J. Med. Chem. 1984, 27, 1127) (7.6 g, 27 mmol) and sodium hydroxide (5.6 g, 5.0 eq.) were dissolved was stirred at room temperature for four hours. After the mixture was neutoralized with hydrochloric acid, the resulting product was diluted by a saturated saline water, extracted with an ethyl acetate and then, dried over a sodium sulfate anhydride. After the solvent was distilled off, the resulting product was recrystallized from a mixed solvent of ethanol and hexane to obtain a 6-amino-3,4-epoxy-3,4-dihydro-2,2-dimethyl-7-nitro-2H-1-benzopyran (1.4 g, 22%) as orange crystals.

Provenance & Evidence