The Acid-catalyzed Decomposition of Diazo Carbonyl Compounds. II. Synthesis of 2- or 5-Heteroatom-substituted Oxazoles
作者:Toshikazu Ibata、Tsuyoshi Yamashita、Makoto Kashiuchi、Shyuji Nakano、Hiroyuki Nakawa
DOI:10.1246/bcsj.57.2450
日期:1984.9
The BF3-catalyzed decomposition of m- and p-substituted α-diazoacetophenones in excess of methyl thiocyanate and ethyl thiocyanate gave the corresponding 2-methylthio-, and 2-ethylthio-5-aryloxazoles, respectively in good yields along with s-alkyl-n-aroylmethylthiocarbamates and α-ethoxyacetophenones. However, yields of 2-dimethylamino-5-aryloxazoles by the reaction of dimethylcyanamide with α-diazoacetophenones
BF3 催化的 m-和 p-取代的 α-重氮苯乙酮在硫氰酸甲酯和硫氰酸乙酯过量时分解,分别得到相应的 2-甲硫基-和 2-乙硫基-5-芳基恶唑以及 s-烷基- n-芳酰基甲基硫代氨基甲酸酯和α-乙氧基苯乙酮。然而,通过二甲基氰胺与α-重氮苯乙酮反应产生的2-二甲氨基-5-芳基恶唑的产率很低。5-二甲氨基-或5-烷氧基-4-芳基-2-甲基恶唑是通过N,N-二甲基-α-(对硝基苯基)重氮乙酰胺或重氮乙酸烷基芳基酯与腈反应制备的。当使用苯基重氮乙酸乙酯或对氯苯基重氮乙酸甲酯时,烷基芳基乙醛酸的酮嗪与恶唑一起获得。