37123-09-4Relevant articles and documents
Synthesis, 1D and 2D NMR spectral assignments, and stereochemical studies of some 4,8,9,10-tetraaryl-1,3-diazaadamantan-6-one oximes
Vengatesh,Sundaravadivelu
, p. 1929 - 1939 (2019/04/17)
A series of 4,8,9,10-tetraaryl-1,3-diazaadamantan-6-one oximes (4a-4e) have been synthesized. 1H and 13C NMR spectra of these oximes were recorded. Chemical shifts have been assigned and the stereochemistry of the compounds was established using 1D and 2D NMR spectral data. A detailed spectral investigation was carried out for one of the representative compounds (4a) with COSY, NOESY, HMQC, HMBC, DEPT-135, and N NMR spectral data. The NMR result clearly indicated the twin chair conformation of the two piperidine rings. The NMR results proved the axial orientation of two aryl groups (C4 and C10) in one piperidine ring and equatorial orientation of two aryl groups (C8 and C9) in another piperidine ring. The effect of allylic (A1,3) interaction between the oxime hydroxyl group and H-5e has been observed. Long-range coupling between H-10e and H-2 which are in ‘W’ arrangement is noted.
Facile denitrosation of Cyclic N-nitrosamines with hydrazoic acid
Ponnuswamy,Akila,Kiruthiga Devi
supporting information, p. 2030 - 2034 (2015/08/18)
A simple and facile method for the denitrosation of cyclic N-nitrosamines using HN3 (concentrated H2SO4+NaN3) is reported. In this method, limited usage of this reagent does not affect the carbonyl group.
Chemistry of N-Nitroso Compounds. 1. Synthesis and Stereodynamics of N-Nitrosopiperidines and N-Nitrosopiperidin-4-ones
Ravindran, Thiruvenkadam,Jeyaraman, Ramasubbu,Murray, Robert W.,Singh, Megh
, p. 4833 - 4840 (2007/10/02)
The stereochemistry of a series of N-nitroso-r-2,c-6-diphenylpiperidin-4-ones (10-15) and N-nitroso-r-2,c-6-diphenylpiperidines (16-18) in solution has been investigated by 1H NMR, 13C NMR, and dynamic 1H NMR spectroscopic studies.Unlike the r-2,c-6-dialkyl-N-nitrosopiperidines, which have diaxial alkyl groups, these N-nitroso-r-2,c-6-diphenylpiperidines (16-18) and N-nitroso-r-2,c-6-diphenylpiperidin-4-ones (10-15) have diequatorial phenyl groups even though the nitroso group is coplanar to the dynamically averaged plane of the piperidine ring.The rotamer populations of the N-NO orientations in the nitrosamines were derived from continuous wave 1H NMR spectral data and are correlated with the steric bulk of the substituents present at the C-3 and C-5 positions.N-Nitroso-r-2,c-6-diphenylpiperidine-4-one (10) was found to have a higher rotational barrier than N-nitroso-r-2,c-6-diphenylpiperidine (16).We attribute this difference to a greater degree of coplanarity (C3-C2-N1-C6-C5) in 10 than in 16.The rotational barriers in 10 were found to decrease as the bulk of the substituents at C3 and C5 increased.The rotational barrier in N-nitroso-r-2,c-6-diphenylpiperidine (16) was found to be lower than the reported rotational barriers of N-nitroso-r-2,c-6-dimethylpiperidine and N-nitroso-2,2,6,6-tetramethylpiperidine.
