将5-取代的2-对乙酰氨基噻吩与等摩尔量的二甲基甲酰胺和磷酰氯在热的二氯乙烷中以良好的产率转化为2-对乙酰氨基噻吩-3-甲醛。然而,在相似的条件下,但是具有三摩尔的磷酰氯,获得了6-氯噻吩并[2,3- b ]吡啶。与三摩尔二甲基甲酰胺一起使用磷酰氯作为溶剂(7摩尔),可以得到6-氯噻吩并-[2,3 - b ]吡啶-5-甲醛的良好收率。类似地,thieno [3,2- b ]-和thieno [3,4- b]-吡啶分别得自3-乙酰氨基噻吩和2,5-二甲基-3-乙酰氨基噻吩。探索了这些反应的机理,并将其与从乙酰苯胺形成相关喹啉中涉及的那些机理进行了比较,并表明它们涉及初始的环甲酰化。显示2-氯喹啉的类似形成具有有限的潜力。
Synthetic approaches to 5,7- and 5,8-dimethoxyquinoline. Sonochemical dehalogenation of substituted 2,4-dichloroquinolines. Use of the 2D COLOC spectrum for the NMR assignment of 5,8-dimethoxyquinoline
作者:A. G. Osborne、J. F. Warmsley
DOI:10.1007/bf00811090
日期:1994.12
Sonochemical dehalogenation of 2,4-dichloroquinoline is very facile. However, with 5,7-dimethoxy-2,4-dichloroquinoline the reaction proceeds stepwise to provide the title dimethoxyquinolines which cannot be prepared via the Skraup reaction. The C-13 NMR chemical shift assignments for 5,8-dimethoxyquinoline are presented. These were made by utilising the coupling connectivities from the bridgehead carbons in the 2D COLOC spectrum.
METH-COHN O.; NARINE B.; TARNOWSKI B., J. CHEM. SOC. PERKIN TRANS., 1981, PART 1, NO 5, 1531-1536