Benzylidene Derivatives of Indene and Cyclopentadiene^1,2

Fulvenes and substituted fulvenes

“…It has already been mentioned (section II.A.2) that some basically substituted dibenzofulvenes have interesting pharmacological properties. Not only the similarity of these dibenzofulvenes with the well-known derivatives of 2,3,6,7-dibenzocyclohepta-2,6-diene and -2,4,6triene leads one to hope that tranquilizers may be found in this series (see, e.g., 101), but also in a small number of cases (19,117) antitumor activity of fulvenes has been reported.…”

“…Carbonyl compounds, which have recently been studied as partners in the preparation of fulvenes, include variously substituted benzaldehydes (19,224), furfural [using diethylamine or sodium methoxide as condensing agents (339,362,363)], furyl ketones (339), the pseudo methyl ester of phthalaldehydic acid (216), a-tetralone (78), cycloalkanones (279), and dicyclopropyl ketone (160). Fulvenes derived from heterocyclic ketones, such as 4-(9-fluorenylidene)-2-flavene (XI) and 4-(1-indenylidene) -2-flavene (XII), can be obtained only indirectly (68,70), as fluorenylsodium, e.g., acts on flavone as well as on 2,6-dimethyl-and -diphenyl-y-pyrone by 1,4 addition to the -pyrone ring, followed by opening of the heterocycles XIII and XV to give the substituted fulvenes XIV and XVI, respectively.…”

Benzylideneindenes with oxygen attached to the indene ring

“…The 1-indanes with methoxy or methyl groups substituted in the aromatic ring were prepared by a cvclodehydration method similar to the procedure of Bone and Cort. 3 The synthesis of 5-methoxy-l-indanone and 7-methoxy-l-indanone was from ß-(ir.-methoxyphenyl)propionic acid. The 6-methoxv-l-indanone was obtained from i3-(¡»-methoxyphenyl)propionic acid.…”

“…The ED6() values in the standard KB tissue culture tests were of the same order of magnitude as for the l-(4methy laminobenzy lidene) indene. 3…”