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FEATURES OF MASS-SPECTRAL FRAGMENTATION ' OF METHYLNITROINDOLIZINES . · .
S. I. Bobrovskii , E . V. Babaev , and Yu . G. Bundel
i -

Vestnik Moskovskogo Universiteta . Vol. 40 , No . 2 , pp. 222-223 , 1985 UDC 543.51:547.75 9

Khimiya ,

metri c method is very informative for the s tudy of the arenes [1] , Results of the study of primary processes of "ation of a series of isomeric methylnltroi ndoiizines, conjrtho- _ 4 i ~ J zCH^ and NO 2 groups in various positions cf the indolizine " L, ai:._:: . ring , ar e r e s 5*" ~ s d ~ r this communication. The main directions of fragmentation eesses with participation of the NOp group (characteristic ar e "h e follcv; yar? ; .ifcrohetarenes on the whole): 1) elimination of he ox r.irroarenes =· ou 2) cleavage of a result cf the ni'tro-nitrite rearrangement ; 3; elimination of the KC radi a result of the "ortho-effect" [2] . The obtained experimental data are c t in the table, together with earlier obtained r.ass spectror.e~ric resu -rs or 2-methyl-6-nitro- and 2-methyl-8-nitroihdoiizines. It is seer, from data table that In the case of 6- and 8-nitrolr.dolizlnes eliminati:n of the roup plays an important role, while for and clisines with an NO 2 group in t ole ring the nitro-nitrite rearrangement Is more characteristi:. , Ar. ana ^CSGUS dependence was observed earlier for isomeri c nitrolr.doles

The mass structure of : mass spectral

C3].

[M - NO| + [M-NO,]* f M -- OH]

Su&slltuant 2-Me-6-NO. [3) 2.7-Me.-6-NO. 2,7-Me.-8-N'O, 2-Me-l-NO. 2-.Me-3-NO2-.Me.|(6-{Nps)j 2,Me-3.6KN-a!5

M

**·

2-Me-8-Na f4j

176 176 190 190 176 176 221

_

0.01 0.06 0.12 0.29 0.40 0,11 0.23

0.7S 0.88 1,12 1.35 0,04 0.20 0.08 0,12

--"

0.60 0,16 0.69 0,17 0,31 0,17

The. most important result is the observed the [M-OH] + peak on the arrangement of CH3 and tetraene skeleton of indolizine, characterized isation of double and single bonds [5]. It was

dependence of the intensity of NO2 groups in relation to the by a significant degree of localfound that the [M-0H]+/M+ ratio " fragment than for

M

by AllenonPress , inc.

':

·

·

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isomers, containing the

/^\
CH, NO,

fragment when the substituents are present both

in the pyrrole and in the pyridine portion of the indozine molecule (table) . The found dependence can be helpful during the structural determination of isomeric methylnitroindolizines. The synthesis of introindolizines and a detailed analysis of mass spectra will be published later. The authors are grateful to Doctor of Chemical Sciences P. B. Terent'ev for helpful discussion. " " Experimental part. Mass spectra were obtained" on an MKr.-13-3 instrument at an ionizaticn energy of 70 eV with direct sample int'roduc-icn into the ion source. . · '. REFERENCES 1.
1979.

R. A. Khmel'nitskii and P. B. Terent'ev, Usp. khimii, vol. 48, p. 854,

2. H. Schwartz, Top..Curr. Chem., vol. 73 , p. 231, 1978. 3. 0. A. Solov'ev, Author's abstract of candidate·s dissertation [in Russian], Moscow, 1975. 4. P. B. Terent'ev, 0. A. Solov'ev, R. A. Khmel'nitskii, S. P. Gromov, and R. S..Sagitullin,- KhGS, no. 6, p. 765, 1982. 5. V. A. Tafeenko and L. A. Aslanov, ZhSKh, vol. 21,. p. 69, 1960. 28 December 1980 ' " ' Department of Organic Cr.eniistry ·