Reaction of ketenes with<i>N,N</i>-disubstituted à-aminomethyleneketones. IX. Synthesis of 2<i>H</i>,5<i>H</i>-pyrano[3,2-<i>c</i>][1]benzopyran derivatives
作者:Luisa Mosti、Pietro Schenone、Giulia Menozzi
DOI:10.1002/jhet.5570170112
日期:1980.1
3-dichloro-3,4-dihydro-5H-pyrano[3,2-c][1]benzopyran-2-ones only in the case of aromatic N-substitution. Dehydrochlorination with triethylamine of these adducts afforded N,N-disubstituted 4-amino-3-chloro-5H-pyrano[3,2-c][1]benzopyran-2-ones in good to moderate yield. The cycloaddition to 3-dimethylaminomethylene-4-chromanone led directly to 3-chloro-4-dimethylamino-5H-pyrano[3,2-c][1]benzopyran-2-one.
将二氯乙烯酮环加成到N,N-二取代的3-氨基亚甲基-4-发色酮上,得到高收率的N,N-二取代的4-氨基-3,3-二氯-3,4-二氢-5 H-吡喃并[3,2- c ] [1]苯并吡喃-2-酮仅在芳族N-取代的情况下。这些加合物用三乙胺脱氯化氢可得到良好产率的N,N-二取代的4-氨基-3-氯-5 H-吡喃并[3,2- c ] [1]苯并吡喃-2-酮。环加成到3-甲基氨基亚甲基-4-苯并二氢吡喃直接导致3-氯-4-二甲氨基-5- ħ吡喃并[3,2- c ^ ] [1]苯并吡喃-2-酮。