Ultrasound assisted synthesis of tetrahydrobenzo[c]xanthene-11-ones using CAN as catalyst

Abstract

Aromatic aldehydes Dimedone Ceric ammonium nitrate (CAN)a b s t r a c t Tetrahydrobenzo[c]xanthenes-11-ones was synthesized by a three component reaction of a-naphthol, aromatic aldehyde and dimedone. Ceric ammonium nitrate acts as a suitable eco-friendly catalyst for this method. Shorter reaction duration, mild reaction condition and low cost make this protocol more effective.

Catalyst Free One-Pot Synthesis of Chromeno Quinolines and Their Antibacterial Activity

“…Xanthenes are usually prepared using 2-naphthol, aldehydes and dimidone as reactants in presence of various catalysts such as Bronsted acidic ionic liquid Triethylamine-bonded sulfonic acid [8], Ionic Liquid Pyrazinium Di (hydrogen sulfate) [9], ionic liquid 1, 3-disulfonicacid imidazolium hydrogensulfate [10], N, N'-dibromo-N, N'-1, 2-ethane diylbis (ptoluenesulfonamide) [11], 3-sulfobutyl-1-(3-propyltriethoxysilane) imidazolium hydrogen sulfate on silica-coated Fe 3 O 4 nanoparticles [12] ammonium chloride [13], silica-bonded imidazolium-sulfonic acid chloride [14], ionic liquid sulfonic acid functionalized pyridinium chloride [15], ZnO nanoparticles [16], ceric ammonium nitrate [17] under solvent free conditions and Bismuth (III) nitrate using water as solvent [18], phosphomolybdic acid using dichloroethane as solvent [19], ceric ammonium nitrate using DCM-ethanol as solvent [20], Thiamine hydrochloride using hexadecyltrimethylammonium bromide (CTAB) in aqueous micellar form as solvent [21] [19] and [21], difficulty to separate the catalyst [13] and [18] and catalyst degradation during the process of the reaction which cannot be recovered [17] [19] and [20]. The main objective of our research is the organic synthesis, which involves green procedures, short reaction time, low temperature conditions, higher yields, and economically desirable processes without any use of catalyst.…”

A Green and Solvent Free Protocol for the Synthesis of Bioactive Tetrahydrobenzo[C]Xanthene-8-Ones Using Novel Ionic Liquid L-Pyrrolidine-2-Carboxylic Acid Sulfate (LPCAS)

“…Moreover, the existing methods have not been conceded for the synthesis of tetrahydrobenzo[c]xanthene-8-ones from 1-naphthol because the electron density at 2-position of 1-naphthol is not sufficient for the formation of corresponding ortho-Quinone Methides (o-QMs). As per our knowledge, only three articles which involve the use of proline triflate [17], CAN [18] and Zeolite [19] Taking to account the weakness of reported methods and to overcome these problems, we have developed the green protocol for efficient synthesis of tetrahydrobenzo[c]xanthenes-8-ones. Herein we used novel ionic liquid; L-pyrrolidine-2-carboxylic acid sulfate (LPCAS) as a catalyst for the synthesis of tetrahydrobenzo[c]xanthenes-8-one derivatives from 1-naphthol ( Scheme 1).…”

N-Sulfonylation of amines, imides, amides and anilides using p-TsCl in presence of atomized sodium in EtOH–THF under sonic condition

“…A thorough literature survey revealed that, there are no reports on the application of atomized sodium in THF under sonication for the sulfonylation reactions. In continuation of our work on the synthesis of organic molecules under ultrasonic condition [22][23][24], we, herein, report a simple, rapid and economical method for the N-sulfonylation of amines, imides, amides and anilides by p-TsCl using atomized sodium in a mixture of EtOH-THF under ultrasonic condition (35 kHz). The process is mild and inexpensive, the yields are very high and the reactions go to completion within 2-8 min as shown in the Scheme 1.…”