Synthesis and study of substituted coumarins. A facile preparation of D,L-<i>o</i>-tyrosine
作者:George Kokotos、Chrysa Tzougraki
DOI:10.1002/jhet.5570230118
日期:1986.1
3-aminocoumarin (XII). Acid hydrolysis of XIII under the above mentioned conditions, (a) and (b), gave XII and 3-hydroxycoumarin (XVI), respectively. Hydrogenation of compound XIII in dioxane or in dimethylformamide with 10% palladium on charcoal gave 3-salicylaminocoumarin (XVII), while hydrogenation of XII, XIII or XVII in acetic acid with traces of water and palladium black gave the amino acid o-tyrosine.
描述了在温和条件下制备氨基香豆素和氨基羟基香豆素的一般程序。通过在碳上含10%钯的情况下用硼氢化钠还原相应的硝基衍生物来制备氨基和乙酰氨基氨基香豆素。(a)在乙醇中的浓盐酸,或(b)1 N的乙酰胺基氨基香豆素的酸水解盐酸在回流下分别得到二氨基香豆素和氨基羟基香豆素。甘氨酸乙酯与水杨醛的缩合得到3-水杨基亚氨基香豆素(XIII),3-氨基香豆素的席夫碱(XII)。在上述条件(a)和(b)下酸水解XIII,分别得到XII和3-羟基香豆素(XVI)。在二恶烷或二甲基甲酰胺中用10%的钯在木炭上氢化化合物XIII得到3-水杨基氨基香豆素(XVII),而XII,XIII或XVII在乙酸中用微量水和钯黑氢化则得到氨基酸邻酪氨酸。