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991.
The catalytic oxidative domino degradation of phenols was investigated. Hydrogen peroxide (30% aq.) was used as an oxidant and 2,2′-dinitro-4,4′-ditrifluoromethyldiphenyl diselenide 4e as a catalyst. The products were muconic acid 5, and muconolactones muconolactones—5-carboxymethylfuran-2(5H)-ones 7 and 9. Phenols with alkyl groups at 2 or 4 positions of the benzene ring were converted regioselectively to corresponding muconolactones substituted at alkenylene ring carbon atoms. The reaction mechanism is proposed. 相似文献
992.
A convenient procedure was developed for the synthesis of geminal bishydroperoxides by the sulfuric acid–catalyzed reaction of ketones with hydrogen peroxide in THF. Gem‐bishydroperoxides were prepared by the reactions of five‐ to seven‐membered cycloalkanones without additional purification in 80–95% yields with a purity of more than 95%; their acyclic analogs were prepared in 43–72% yields. 相似文献
993.
《合成通讯》2013,43(17):3071-3076
Abstract The treatment of 4-(2′-hydroxyaryl)-2-(N,N-dialkylamino)-1,3-dithiolium perchlorates (1a–g) with sodium sulfide nonahydrate in ethanol at room temperature affords the corresponding 1,3-dithiole-2-thiones (2a–g). When these reactions are conducted in boiling ethanol, 2′-hydroxyacetophenones (3a–g) have been obtained in good to excellent yield. A tentative mechanism for the formation of 3a–g shows that this reaction is regioselective, this being established by the presence of hydroxyl group in 2′-position. That has been confirmed in a control experiment, 4-phenyl-2-(piperidin-1-yl)-1,3-dithiolium perchlorate affording a mixture of condensation products of acetophenone and phenylacetaldehyde, under similar reaction conditions. 相似文献
994.
Ganta Madhusudhan Reddy V. V. N. K. V. Prasada Raju J. Moses Babu Ch. Praveen Mayur Khunt K. Mukkanti 《合成通讯》2013,43(11):1725-1736
Tenatoprazole (Ulsacare®) is a recently developed antiulcerative drug used for the treatment of both erosive and nonerosive gastroesophageal reflux disease. During the bulk synthesis of tenatoprazole, we have observed four impurities (tenatoprazole N‐oxide, tenatoprazole sulfone N‐oxide, N‐methyl tenatoprazole, and desmethoxy tenatoprazole) and two metabolites (tenatoprazole sulfide and tenatoprazole sulfone). The present work describes the synthesis and characterization of these impurities. 相似文献
995.
Biswanath Das Yallamalla Srinivas Chittaluri Sudhakar Kongara Damodar Ravirala Narender 《合成通讯》2013,43(2):220-227
Bromination of alkenes and alkynes has efficiently been carried out at room temperature in short reaction times using KBr and diacetoxy iodobenzene in CH2Cl2-H2O (1:1) to prepare the corresponding trans-dibromo compounds in excellent yields. 相似文献
996.
Primary thioamides are prepared in moderate to excellent yields by treating nitriles with sodium hydrogen sulfide and diethylamine hydrochloride in an appropriate solvent with mild heating. 相似文献
997.
A new and efficient method to synthesize a 3,3,6,6,9‐aryl‐1,8‐dioxo‐octahydroxanthene derivative using diammonium hydrogen phosphate as catalyst was performed in water at room temperature in a short periods. 相似文献
998.
Saeed Balalaie Morteza Bararjanian Masoumeh Sheikh‐Ahmadi Shohreh Hekmat Peyman Salehi 《合成通讯》2013,43(7):1097-1108
Diammonium hydrogen phosphate was used as a mild, efficient, neutral, and cheap catalyst for the synthesis of various 4H‐benzo[b]pyran derivatives via a one‐pot, three‐component condensation of aromatic aldehydes, active methylene compounds, and dimedone in aqueous media. 相似文献
999.
A novel and environmentally benign synthetic method for ureas through hydrogen peroxide–promoted desulfurization of thioureas at room tepemperature via grinding is reported. As compared with the traditional method, this one is manipulatively simple and the oxidant is low cost, highly active, and environmentally friendly. 相似文献
1000.
《合成通讯》2013,43(14):1865-1874
Abstract Aerobic oxidation of aralkanes and α,β‐unsaturated carbonyl compounds in the presence of a catalytic amount of N‐hydroxyphthalimide (NHPI) and 2,2′‐Azobis(4‐methoxy‐2,4‐dimethylvaleronitrile) (V‐70) under 1 atmos. of oxygen at 30°C gave α‐hydroperoxyaralkanes and γ‐hydroperoxy‐α,β‐unsaturated carbonyl compounds, respectively. 相似文献