Silica supported perchloric acid (HClO4-SiO2): A mild, reusable and highly efficient heterogeneous catalyst for the synthesis of 14-aryl or alkyl-14-H-dibenzo[a,j]xanthenes

Boron sulfonic acid (BSA) catalyzed selective synthesis of aryl-bis(2-hydroxynaphth-1-yl)methanes and 14-alkyl- and 14-aryl-14H-dibenzoxanthenes under solvent-free condition

“…The products were identified by comparison of their FT-IR, 1 H and 13 C NMR spectroscopic data with those of authentic compounds and literature reported data. 17,24,[26][27][28] The elemental analysis were performed on Perkin Elmer 20-analyzer. Melting points were recorded in a Buchi B-540 melting point apparatus and were uncorrected.…”

“…H NMR, 13 C NMR and elemental analysis data with reported literature. 24,17,[26][27][28] Cinnamaldehyde produced dibenzoxanthene 4i as single product under microwave and thermal energies (Table 2, entry 9). Butanal formed dibenzoxanthene as major product in thermal method at 90°C with 10 mol% of BSA (Table 2, entry 6).…”

Microwave-assisted solvent-free synthesis of 14-aryl/alkyl-14H-dibenzo[a,j]xanthenes and tetrahydrobenzo[a]xanthen-11-ones catalyzed by nano silica phosphoric acid

“…The best procedure for synthesis of 14-aryl/alkyl-14H-dibenzo [a,j]xanthene is the mixing of 2-naphthol with aldehydes in the presence of a catalyst. This procedure have been catalyzed with silica sulfuric acid 4,5 , Dowex-50W 6 , sulfamic acid 7 , HClO 4 -SiO 2 8 , cyanuric chloride 9 , BF 3 .SiO 2 10 and InCl 3 11 . Tetrahydrobenzo[a]xanthenes-11-ones as benzoxanthene derivatives could be synthesized via one pot condensation of 2-naphthol, aldehydes and 1,3-diketones in the presence of an acidic catalyst.…”

Condensation Reactions between Aldehydes andβ-Naphthol Catalyzed by Silicotungstic Acid

“…近年来, 人 们对于氧杂蒽的合成进行了大量的研究, 可由 2-羟基苯 甲醛与 2-四氢萘酮缩合 [7] , 以及苯甲醛与苯乙酮反应 [8] 制得. 最常用的方法则是通过 β-萘酚与脂肪醛或芳香醛 的 缩 合 , 用 于 该 反 应 的 催 化 剂 主 要 有 K 5 CoW 12 O 40 • 3H 2 O [9] , 硫 酸 氢 钠 [10] , 煤 基 活 性 炭 负 载 硫 酸 [11] , HClO 4 -SiO 2 [12] , P 2 O 5 或 InCl 3 [13] , LiBr [14] , Fe(HSO 4 ) 3 [15] , 草酸 [16] , 离子液体 [17] , 对甲苯磺酸 [18] , 氨基磺酸 [19] , NaHSO 4 /SiO 2 [20] , BF 3 /SiO 2 [21] , 磺 化 硅 胶 [22] , 蒙 脱 石 K10 [23] 等, 但以上这些方法或多或少存在着反应时间长, 反应温度高, 催化剂制备复杂等缺点. 杂多酸是由中心 原子(如 P, Si, As, Ge [29] 5 H a 3e 31 201～203 202～202.5 [30] 6 CH 3 3f 42 167～169 168.5～169 [29] a The substrate was 37% formaldehyde solution.…”

“…杂多酸是由中心 原子(如 P, Si, As, Ge [29] 5 H a 3e 31 201～203 202～202.5 [30] 6 CH 3 3f 42 167～169 168.5～169 [29] a The substrate was 37% formaldehyde solution. [12] 10 H a 4j 60 47 202～203 202 [32] 11 CH 3 4k 50 63 154～156 155～157 [11] 12 CH 3 CH 2 4l 50 58 150～152 151～153 [31] a The substrate was 37% formaldehyde solution.…”