161196-99-2Relevant articles and documents
Ammonium Chloride-Promoted Rapid Synthesis of Monosubstituted Ureas under Microwave Irradiation
Lan, Chunling Blue,Auclair, Karine
supporting information, p. 5135 - 5146 (2021/10/19)
Monosubstituted ureas are important scaffolds in organic chemistry. They appear in various biologically active compounds and serve as versatile precursors in synthesis. Monosubstituted ureas were originally prepared using toxic and hazardous phosgene equivalents. Modern methods include transamidation of urea and nucleophilic addition to cyanate salts, both of which suffer from a narrow substrate scope due to the need for a strong acid and prolonged reaction times. We hereby report that ammonium chloride can promote the reaction between amines and potassium cyanate to generate monosubstituted ureas in water. This method proceeds rapidly under microwave irradiation and tolerates a broad range of functional groups. Unlike previous strategies, it is compatible with other nucleophiles, acid-labile moieties, and most of the common protecting groups. The products precipitate out of solution, allowing facile isolation without column chromatography.
Bismuth trichloride–mediated cleavage of phenolic methoxymethyl ethers
Obaro-Best, Oghale,Reed, Jack,Norfadilah, Alya A. F. B.,Monahan, Ryan,Sunasee, Rajesh
supporting information, p. 586 - 593 (2016/06/08)
A simple and efficient method for removal of phenolic methoxymethyl ethers in the presence of 30?mol% of bismuth trichloride in acetonitrile/water is described. Notable features of the cleavage protocol entail use of an ecofriendly bismuth reagent, ease of handling, low cost, operational simplicity, and good functional group compatibility. A number of structurally varied phenolic methoxymethyl ethers were cleaved in good to excellent yields.
Practical one-pot conversion of aryl bromides and β-bromostyrenes into aromatic nitriles and cinnamonitriles
Ishii, Genki,Harigae, Ryo,Moriyama, Katsuhiko,Togo, Hideo
, p. 1462 - 1469 (2013/02/25)
Various aryl bromides were efficiently converted into the corresponding aromatic nitriles in good yields by the treatment with Mg turnings and subsequently DMF, followed by treatment with molecular iodine and aq NH 3. The same treatment of aryl bromides, which are weakly reactive to Mg turnings, with iPrMgCl·LiCl and subsequently DMF, followed by the treatment with molecular iodine and aq NH3 also afforded the corresponding aromatic nitriles in good yields. On the other hand, when N-formylpiperidine was used instead of DMF, p-substituted β-bromostyrenes were converted into the corresponding p-substituted cinnamonitriles, i.e., α,β-unsaturated nitriles, in good to moderate yields by the same procedure. The reactions were carried out by means of a simple experimental procedure and did not require any toxic metal cyanides or expensive rare metals. Therefore, the present reactions are practical and environmentally benign one-pot methods for the preparation of aromatic nitriles, cinnamonitriles, and aliphatic nitriles from aryl bromides, β-bromostyrenes, and alkyl bromides, respectively, through the formation of Grignard reagents and their DMF or N-formylpiperidine adducts.
