A practical approach for the preparation of monofunctional azulenyl squaraine dye
作者:Wellington Pham、Ralph Weissleder、Ching-Hsuan Tung
DOI:10.1016/s0040-4039(03)00819-0
日期:2003.5
The synthesis of monofunctional azulenyl squaraine dye NIRQ(700) is described. The essential azulene intermediate 3, 1-(methoxycarbonyl)-2-methylazulene, was achieved via [8+2] cycloaddition between lactone 2, 2H-3-methoxycarbonyl-cyclohepta[b]furan-2-one, and the in situ generated vinyl ethers under high temperature and pressure conditions. Methylation on the cycloheptatriene ring of 2-methyl azulene
描述了单官能薁基方酸菁染料 NIRQ(700) 的合成。通过内酯 2, 2H-3-甲氧基羰基-环庚 [b] 呋喃-2-one 之间的 [8+2] 环加成反应,获得了必需的 azulene 中间体 3, 1-(甲氧基羰基)-2-methylazulene,并原位生成高温高压条件下的乙烯基醚。按照 Schrott 的方法,通过 Meisenheimer 型中间体在 2-甲基 azulene 6 的环庚三烯环上进行甲基化,形成羧酸中间体 9, 3-(2-甲基-azulen-4-yl)-丙酸。9与方酸的缩合以中等产率提供标题化合物NIRQ(700)。