Structural Investigation and Preparation of 14-alkyl-14H-dibenzo[a,j]xanthenes revised

Abstract

ABSTRACT. Prepartion of the title compounds at 0-5 o C is reported along with their AM1 SCF MO calculations. The advantage of this procedure is the hight purity of the products.

Ferric hydrogensulfate catalyzed synthesis of aryl 14H-dibenzo[a,j] xanthene derivatives under thermal and solvent-free conditions

“…9,10 Furthermore, benzoxanthenes are used as dyes, 11 in laser technologies, 12 and in fluorescent materials. 13 The synthesis of 14H-dibenzo[a,j]xanthene is generally achieved by a) dehydration of bis(2-hydroxy-1-naphthyl) methane using POCl 3 14 or by boiling acetic acid diester of bis(2-hydroxy-1-naphthyl) methane, 15 b) condensation of -naphthol with aliphatic and aromatic aldehydes in the presence of hydrochloric acid or phosphoric acid 16 and also sulfuric acid 17 in acetic acid as solvent. All these methods suffer from harsh reaction conditions, long reaction times, unsatisfactory yields and tedious experimental procedures.…”

Catalytic application of two novel sandwich-type polyoxometalates in synthesis of 14-substituted-14H-dibenzo[a, j]xanthenes

“…27,28 However, those methods suffer from significant limitations, such as low yields of products, the need for a prolonged reaction time (from 16 h to 5 days), large quantities of solvent and catalyst involved, and harsh reaction conditions. Recently, benzoxanthenes was obtained by the condensation reaction between β-naphthol with aliphatic or aromatic aldehydes in the presence of hydrochloric acid or phosphoric acid, 29 sulphuric acid, 30 p-toluenesulphonic acid, 31 sulphamic acid, 32 Amberlyst-15, 33 HClO 4 -SiO 2 , 34 Dowex-50W, 35 Yb(OTf) 3 , 36 alum, 37 Montmorillonite K-10, 38 heteropoly acid, 39 P 2 O 5 or InCl 3 40 and indion-130 41 as catalyst.…”

Facile Catalyzed Preparation of 14‐Aryl‐ or Alkyl‐14‐H‐dibenzo[a,j]xanthenes by Dodecylphosphonic Acid and Dodecylsulfamic Acid: Environmentally Benign Methods

“…Many synthetic methods exist for the synthesis of benzoxanthenes, such as the cyclocondensation reaction of 2‐hydroxyaromatic aldehydes and 2‐tetralone , the reaction of benzaldehyde and acetophenone , and the condensation of β‐naphthol with alkyl or aryl aldehydes. The latter synthetic method can be promoted by many Brønsted acid catalysts such as H 2 SO 4 , p ‐toluenesulfonic acid , sulfamic acid , methanesulfonic acid , H 3 PO 4 or HClO 4 at 0°C in acetic acid , HCl , heterogonous solid acids such as Montmorillonite K10 , Indion‐130 , and Amberlyst‐15 , heteropolyacid , cellulose sulfuric acid , [MIMPS]HSO 4 , BSA , and NaHSO 4 /SiO 2 . However, many of these procedures have significant drawbacks such as low yields, long reaction times, difficulties in work‐up, use of an excess of reagents/ catalysts, harsh reaction conditions, and use of toxic organic solvents.…”