A direct anionic cyclization of 2-alkynylbenzonitrile to 3-substituted-1(2H)-isoquinolones and 3-benzylideneisoindol-2-ones initiated by methoxide addition
Mj. Wu et al., A direct anionic cyclization of 2-alkynylbenzonitrile to 3-substituted-1(2H)-isoquinolones and 3-benzylideneisoindol-2-ones initiated by methoxide addition, TETRAHEDRON, 55(46), 1999, pp. 13193-13200
Treatment of 2-(2-alkylethynyl)benzonitrile with sodium methoxide in reflux
ing methanol for 12 h gave 3-alkyl-1(2H)-isoquinolone in modest yield. Unde
r the same reaction conditions, methanolysis of 2-(2-arylethynyl)benzonitri
le lead to the formation of 3-alkylidene isoindol-1-one. Partial hydrolysis
of 2-(1-hexynyl)benzonitrile to the corresponding benzamide, followed by t
reatment of the benzamide with sodium methoxide in refluxing methanol gave
3-pentylidene isoindol-1-one in 49% yield. This suggests that the benzamide
is not involved in this cyclization reaction. (C) 1999 Elsevier Science Lt
d. All rights reserved.