673-66-5Relevant articles and documents
Ethyl 2-Cyano-2-(2-nitrobenzenesulfonyloxyimino) Acetate (ortho-NosylOXY)-Mediated Double Beckmann Rearrangement of Ketoximes under Microwave Irradiation: A Mechanistic Perception
Dev, Dharm,Kalita, Tapasi,Mondal, Tanmay,Mandal, Bhubaneswar
, p. 1427 - 1435 (2021/01/04)
A method for Beckmann rearrangement using ethyl 2-cyano-2-(2-nitrobenzenesulfonyloxyimino) acetate (o-NosylOXY) under microwave irradiation is reported. Ketoximes (19 examples) are converted to the corresponding amides/lactams with 69–97% yields in ～10 minutes without any Lewis acid or co-catalyst. This is an example of halogen-free organocatalytic Beckmann rearrangement. Nuclear magnetic resonance (NMR)- and high-resolution mass spectrometry (HRMS)-based detailed mechanistic investigation suggest that o-NosylOXY acts as an initiator. Such initiators are reported before based on density functional theory (DFT) calculations. However, we report here the HRMS signatures of two transient intermediates, the nitrilium ion and the nitrilium ion's dimeric species. Rigorous NMR-based investigation of the reaction mechanism is performed. Our results indicate that the reported Beckmann rearrangement proceeds via two consecutive rearrangements. (Figure presented.).
Synthesis method 7- aminoheptanoic acid hydrochloride
-
Paragraph 0033-0042, (2020/03/16)
The invention discloses a synthesis method 7 - of, aminoheptanoic acid hydrochloride, belongs to the field: organic synthesis, and the reaction solution obtained by adding the cycloheptanone to the methanol solution, and adding concentrated HCl, to obtain, aminopimelic acid hydrochloride, is more suitable for large-scale production, by adding concentrated hydrochloric acid, reflux reaction 7 - to dichloromethane cooling crystallization. for producing the heptane lactam, in simple operation, of the present invention.
In Situ Conformational Fixation of the Amide Bond Enables General Access to Medium-Sized Lactams via Ring-Closing Metathesis
Hegmann, Nina,Prusko, Lea,Diesendorf, Nina,Heinrich, Markus R.
supporting information, p. 7825 - 7829 (2019/01/04)
In this work, a novel phenethylamine-derived protecting group is introduced, which is able to significantly enhance the Grubbs I-catalyzed formation of 9- to 12-membered lactams through charge-induced conformational fixation under acidic conditions. As the new approach is particularly valuable for 10- and 11-membered ring systems, for which no related precedence was available so far, the overall strategy now offers general access to medium-sized lactams via ring closing metathesis. Cleavage of the protecting group can be achieved through a mild sequence combining N-oxidation and Cope elimination or alternatively under standard hydrogenation conditions.
