Acetic Anhydride → N-[3,4-dihydro-2-[[(tetrahydro-2H-pyran-2-yl)oxy]methyl]-2H-1-benzopyran-6-yl]-acetamide

Participants

Reaction Steps

To a stirred mixture of 5.3 parts of 3,4-dihydro-2-[[(tetrahydro-2H-pyran-2-yl)oxy]methyl]-2H-1-benzopyran-6-amine and 50 parts of pyridine were added dropwise 2.25 parts of acetic acid anhydride at a temperature below 10° C. Upon completion, stirring was continued for 10 minutes in an ice bath. The whole was stirred for 3 hours at room temperature. The reaction mixture was evaporated. Water was added to the residue. The product was extracted with 1,1'-oxybisethane. The organic layer was washed with water, dried, filtered and evaporated, yielding 5 parts (82%) of N-[3,4-dihydro-2-[[(tetrahydro-2H-pyran-2-yl)oxy]methyl]-2H-1-benzopyran-6-yl]-acetamide as an oily residue (intermediate 11).

Provenance & Evidence