Journal of Physical Organic Chemistry p. 115 - 122 (2002)
Update date:2022-08-03
Topics:
Daszkiewicz, Zdzislaw
Spaleniak, Grzegorz
Kyziol, Janusz B.
Para-substituted N-phenylnitramines were prepared either by oxidation of diazonium salts or by nitration under alkaline or acidic conditions. Isotopic [15N-NO2] labelling indicated that the bands characteristic of the N-nitro group appear in the 1318-1323 and 1585-1607 cm-1 regions. In the nitrogen NMR spectra, the nitramino group gives two resonances at -193 ± 3 (NH) and -32 ± 3 ppm (NO2). The chemical shifts in proton and carbon NMR spectra are predictable, based on increments and the additivity rule. The spectral data indicate the lack of conjugation between the nitramino group and another substituent bound to the ring. It seems to contradict the well-known fact that substituents strongly (ρ = 4) influence the rate of nitramine rearrangement. The acidities of primary N-phenylnitramines (3.77 < pKA < 5.62) are similar to those of benzoic acids and weakly dependent (ρ = 1) on the electronic character of a substituent. Based on the analogy with benzoic acids, it has been calculated that basicities of nitramines (pKB ≈ 21) are extremely low. Consequently, addition of protons to an intact nitramine molecule, as the preliminary step of the rearrangement, seems to be improbable. Migration of the N-nitro group precedes protonation; the latter process facilitates transformation of intermediates into stable final products. Copyright
View MoreShandong Xingshun New Material Co., Ltd.
website:http://www.sd-xingshun.com
Contact:+86-519-86461196/+86-519-86464994
Address:Middle of Luhua East Road, Dingtao District
Contact:086-027-83820093
Address:16#luojiashan, wuchang district
ZHONGBEI NORTHLAND BIO-CHEM INDUSTRY CO.,LTD
Contact:+86-452-6055586
Address:5F, C Liandalijing Bulding,No 259 Xinjiang Road, Jianhua District
Geen Chemical Technology Co., Ltd
Contact:86-769-21660847
Address:1408, Yingfeng Commercial Center, Nancheng District
Jiacheng-Chem Enterprises Limited
Contact:86-571-86711508
Address:19 Floor, CIBC Holley International Building, No. 198,Wuxing Road, Hangzhou, China,310020
Doi:10.1016/S0040-4039(01)90212-6
(1984)Doi:10.1016/S0957-4166(03)00533-0
(2003)Doi:10.1002/anie.201915875
(2020)Doi:10.1002/macp.1976.021771003
(1976)Doi:10.1016/j.bmcl.2005.02.009
(2005)Doi:10.1002/ejoc.201701021
(2017)