Fluorene Derivatives Bearing Two to Seven Phthalimidomethyl Groups: Syntheses, Crystal Structures and Conversion to Amines

Abstract

Fluorene derivatives containing four to seven phthalimidomethyl groups (1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl-methyl groups) were prepared from 9H-fluorene, 9,9-diethyl-9H-fluorene as well as from 2,7-and 2,4,7-functionalized 9,9-diethyl-9Hfluorenes by using the conditions of the Tscherniac-Einhorn reaction. By reacting the 9,9-diethyl substituted fluorenes with N-(hydroxymethyl)phthalimide the 2,4,6,7-and 2,3,4,6,7-substituted derivatives were obtained. In the absence of the ethyl groups, as in the case of 9H-fluorene, the formation of the sixfold and sevenfold substituted compounds was observed (

Compounds Derived from 9,9‐Dialkylfluorenes: Syntheses, Crystal Structures and Initial Binding Studies (Part II)

“…9,9‐Diethyl‐9 H ‐fluorene‐2,4,7‐tricarbaldehyde [9,10a,b] and 2,4,7‐tris(bromomethyl)‐9,9‐diethyl‐9 H ‐fluorene [9,10a] were found to be useful starting materials for the synthesis of a wide range of 2,4,7‐trisubstituted 9,9‐diethyl‐9 H ‐fluorenes [3,4] . Compound 1 was prepared on the basis of two reaction pathways using the aforementioned starting materials (compounds 6 and 7 in Schemes 1 and 2, respectively).…”

“…The series of 2,4,7-trisubstituted 9,9-diethyl-9H-fluorenes bearing different functional groups, the syntheses of which we have recently described, [3,4] is extended by the 9,9-dialkylfluorenes synthesized in the present studies (target molecules 1-3 and intermediates 9, 10, 13 and 14). The new fluorenes, which contain aminopyridine-based recognition units and have ethyl, hexyl or dodecyl groups in the 9-position of the fluorene backbone, were prepared using 2,4,7-tris(bromomethyl)-9,9dialkyl-9H-fluorenes and 9,9-diethyl-9H-fluorene-2,4,7-tricarbaldehyde as educts.…”

“…Recently, we have reported the syntheses of a series of 2,4,7-trisubstituted 9,9-diethyl-9Hfluorenes [3] as well as of 9,9-diethyl-9H-fluorenes bearing four to seven functionalized side-arms. [4] Here we describe the synthesis of further representatives of 2,4,7-trisubstituted 9,9-dialkyl-9H-fluorenes containing pyridinyl groups (compounds 1-3, Figure 1). In addition, compounds 4 and 5, the syntheses of which we have described previously, [3] are also considered in this study.…”

“…Due to the numerous possible applications of fluorenes, the synthesis of new representatives of this class of compounds is the subject of intensive research. Recently, we have reported the syntheses of a series of 2,4,7‐trisubstituted 9,9‐diethyl‐9 H ‐fluorenes [3] as well as of 9,9‐diethyl‐9 H ‐fluorenes bearing four to seven functionalized side‐arms [4] …”