Sulfamic acid catalyzed solvent-free synthesis of 10-aryl-7,7-dimethyl-6,7,8,10-tetrahydro-9H-[1,3]-dioxolo [4,5- b]xanthen-9-ones and 12-aryl-9,9-dimethyl-8,9,10,12-tetrahydro-11H-benzo[a]xanthen-11-ones

Abstract

Three-component one-pot synthesis of some novel 10-aryl-7,7-dimethyl-6,7,8,10-tetrahydro-9H-[1,3]-dioxolo[4,5-b]xanthen-9-ones, which have not been published before, and 12-aryl-9,9-dimethyl-8,9,10,12-tetrahydro-11H-benzo[a]xanthen-11-ones from condensation of 3,4-methylenedioxyphenol or β-naphthol, aldehydes and dimedone under solvent-free conditions at 120 °C is reported.

Sulfamic acid as energy efficient catalyst for synthesis of flurophores, 1-H-spiro [isoindoline-1,2′-quinazoline]-3,4′(3′H)-diones

“…The properties like nonvolatile, noncorrosive, stable, low-cost, easy commercial availability, etc., have triggered their use as catalyst of choice in number of organic transformations. [38][39][40][41] In recent years, we have reported SA as an effective catalyst for the synthesis of 1,2,4-triazole-3-thiones, spiroindoloquinoxaline, and substituted-5-deazaoxaflavins. [42][43][44] Our earlier experience with SA and interest in the synthesis of heterocycles, prompted us to explore SA for the synthesis of 1-H -spiro[indoline-3,2 -quinazoline]-2,4-(3-H )-diones.…”

H4SiW12O40 Catalyzed One‐Pot Synthesis of 12‐Aryl‐8,9,10,12‐tetrahydrobenzo[a] Xanthen‐11‐ones Under Solvent‐Free Conditions

“…The solid product was purified by recrystallization from EtOH to afford the pure product. All compounds are known and their physical and spectroscopic data were in good agreement with those of authentic samples [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] .…”

Microwave assisted green synthesis of pharmaceutically potent benzoxanthone analogues employing biodegradable oxalic acid as ecofriendly catalyst

“…The Mechanism of the reaction is shown in Scheme 2. The synthesis of benzoxanthone has been reported in the presence of strontium triflate [17], InCl 3 , P 2 O 5 [18], NaHSO 4 -SiO 2 [19], HClO 4 [20], pTSA [21], Cu-SiO 2 [22], Caro acid [23], Cyanouric chloride [24] (2,4,6-trichloro-1,3,5-triazine), Camphor sulphonic acid [25], Dodecatungstophosphoric acid [26], iodine [27], RuCl 3 .nH 2 O [28], Calix-4-arene sulphonic acid [29], Sulfamic acid [30], ClSO 3 H [31], Silica-sulphuric acid [32], TBAF [33], Proline triflate [34], Zr(HSO 4 ) 2 [35], ZnO(NPs) [36], SiWA [37], HBF 4 /SiO 2 , [38] [bmim][BF4] [39],Ceric ammonium nitrate (CAN) [40]. However, all the methodologies mentioned above suffer from one or more shortcomings such as the use of toxic and hazardous catalysts, solvents, harsh reaction conditions, prolonged reaction time, high temperature, low yield and so on.…”