منابع مشابه
POSITIVE AND NEGATIVE ION MASS SPECTRA OF RING - SUBSTITUTED NITROBENZENES
The 70 ev positive and negative ion mass spectra of ring-substituted nitrobenzenes were studied. The influence of the substituent group on the fragmentation modes of the molecular ions is discussed. The effect of pressure in the formation of negative ions was also studied. As expected, the ratio of fragment ions to negative molecular ions decreased with increasing pressure in ion source.
متن کاملN 4-(3-Bromophenyl)quinazoline-4,6-diamine
In the title compound, C(14)H(11)BrN(4), the fused benzene and pyrimidine rings are nearly coplanar, making dihedral angles of 1.26 (14) and 3.53 (15)° in the two independent mol-ecules. In the crystal structure, π-π stacking inter-actions [centroid-centroid distances = 3.4736 (19) and 3.5416 (19) Å] and weak N-H⋯N and N-H⋯Br inter-actions contribute to the stability of the structure.
متن کاملAlkaloid N-oxides of Amaryllidaceae
Ungiminorine N-oxide was isolated from Puncrutium maritimum, and homolycorine N-oxide and O-methyl lycorenine N-oxide from Lapiedra martinezii. These compounds represent the first examples of naturally occurring Noxides from the Amaryllidaceae.
متن کاملREACTIVITY OF N-SUBSTITUTED p-BENZO AND p-NAPHTHOQUINONEIMINE N-OXIDES TOWARD DIPOLAROPHILES
The dipolar cycloaddition reactivity of N-(1-naphthy1)-1,4- benzoquinoneimine N-oxide and N-phenyl-1,4- naphthoquinoneimine Noxide are investigated, The latter gives the expected adducts with common dipolarophiles such as acrylonitryle, methyl methacrylate, dimethylacetylene dicarboxylate and N-phenylmaleimide. The reactivity of the former nitrone is found to be minimal. It undergoes, how...
متن کاملBridgehead nitrogen heterocycles which contain the quinazoline moiety -- synthesis and cycloaddition of 1,2-dihydroquinazoline 3-oxides.
A novel synthesis of 1,2-disubstituted 1,2-dihydroquinazoline 3-oxides 8 and the first ever examples of 1,3-dipolar trapping of these nitrones to homonuclear dipolarophiles is described. The new dipoles 8 reacted with N-methyl maleimide, generating diastereomeric adducts 14-16. In the reaction between 8 and dimethyl acetylenedicarboxylate, primary cycloadducts 17 and/or stable rearrangement pro...
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ژورنال
عنوان ژورنال: Journal of the Mass Spectrometry Society of Japan
سال: 1973
ISSN: 1884-3271,1340-8097
DOI: 10.5702/massspec1953.21.245