Sodium borohydride → N,2,2-trimethyl-3,4-dihydro-3-hydroxy-6-nitro-2H-1-benzopyran-4-carbothioamide

Participants

Reaction Steps

To a mixture of 2.08 g of N-methyl-6-nitro-3-hydroxy-2,2-dimethyl-2H-1-benzopyran-4-carbothioamide and 50 ml of methanol was added 1.33 g of sodium borohydride at -10° C. while stirring. The mixture was stirred for 24 hours while slowly raising the temperature from -10° C. up to room temperature, followed by concentration under reduced pressure. Water was added to the residue, and the mixture was extracted with methylene chloride. The organic layer was washed with a saturated sodium chloride aqueous solution, dried over magnesium sulfate, and concentrated under reduced pressure. The residue was recrystallized from a mixed solvent of methylene chloride and n-hexane to obtain 0.6 g of N-methyl-6-nitro-3,4-dihydro-3-hydroxy-2,2-dimethyl -2H-1-benzopyran-4-carbothioamide.

Provenance & Evidence