16251-47-1Relevant articles and documents
A General Catalytic Method for Highly Cost- and Atom-Efficient Nucleophilic Substitutions
Huy, Peter H.,Filbrich, Isabel
supporting information, p. 7410 - 7416 (2018/04/30)
A general formamide-catalyzed protocol for the efficient transformation of alcohols into alkyl chlorides, which is promoted by substoichiometric amounts (down to 34 mol %) of inexpensive trichlorotriazine (TCT), is introduced. This is the first example of a TCT-mediated dihydroxychlorination of an OH-containing substrate (e.g., alcohols and carboxylic acids) in which all three chlorine atoms of TCT are transferred to the starting material. The consequently enhanced atom economy facilitates a significantly improved waste balance (E-factors down to 4), cost efficiency, and scalability (>50 g). Furthermore, the current procedure is distinguished by high levels of functional-group compatibility and stereoselectivity, as only weakly acidic cyanuric acid is released as exclusive byproduct. Finally, a one-pot protocol for the preparation of amines, azides, ethers, and sulfides enabled the synthesis of the drug rivastigmine with twofold SN2 inversion, which demonstrates the high practical value of the presented method.
Carbon dioxide as a carbonylating agent in the synthesis of 2-oxazolidinones, 2-oxazinones, and cyclic ureas: Scope and limitations
Paz, Jairo,Perez-Balado, Carlos,Iglesias, Beatriz,Munoz, Luis
supporting information; experimental part, p. 3037 - 3046 (2010/07/15)
Carbon dioxide can be used as a convenient carbonylating agent in the synthesis of 2-oxazolidinones, 2-oxazinones, and cyclic ureas. The transient carbamate anion generated by treating a primary or secondary amine group in basic media can be activated with phosphorylating agents such as Diphenylphosphoryl azide (DPPA) and Diphenyl chlorophosphate (DPPCl) but also with other types of electrophiles such as SOCl2, TsCl, or AcCl. The intramolecular trapping of the activated carbamate by a hydroxyl group leads to the formation of 2-oxazolidinones or 2-oxazinones in good to excellent yields. This methodology was successfully applied to the synthesis of cyclic ureas up to 7-membered rings from the corresponding diamines.
Pure by NMR ?
Claridge, Timothy D. W.,Davies, Stephen G.,Polywka, Mario E. C.,Roberts, Paul M.,Russell, Angela J.,Savory, Edward D.,Smith, Andrew D.
body text, p. 5433 - 5436 (2009/06/06)
(Chemical Equation Presented) Integration of a 13C-1H satellite peak of a given 12C-1H parent resonance within a quantitative 1H NMR spectrum and comparison to the minor component represents a simple protocol for the accurate determination of diastereoisomeric ratios of up to 1000:1 (i.e., 99.8% de).