caa a22 4500 605530181 CHVBK 20210128100822.0 cr unu---uuuuu 210128e20150401xx s 000 0 eng 10.1134/S1070428015040144 doi (NATIONALLICENCE)springer-10.1134/S1070428015040144 Mass spectra of new heterocycles: XIII. Fragmentation of 2-(prop-1-en-1-yl)-4,5-dihydro-1,3-thiazoles under electron impact and chemical ionization [Elektronische Daten] [L. Klyba, N. Nedolya, O. Tarasova, E. Sanzheeva] Fragmentation of 2-(prop-1-en-1-yl)-4,5-dihydro-1,3-thiazoles synthesized from alkoxyallenes or propargylbenzene, isothiocyanates, and benzyl, allyl, or propargyl bromide has been studied under electron impact (70 eV) and chemical ionization (with methane as reactant gas). All compounds under electron impact give rise to stable molecular ions whose decomposition involves concurrent dihydrothiazole ring cleavage and elimination of substituents. The fragmentation pattern is largely determined by the nature of the substituent on C5. Chemical ionization of 4,5-dihydro-1,3-thiazole derivatives is typically accompanied by protonation and electrophilic addition with subsequent elimination of nitrile molecule. No substituent effect on the fragmentation pattern under chemical ionization has been revealed. Unlike electron impact and chemical ionization, the most abundant ion in the MALDI mass spectrum of 2-[(Z)-1-butoxyprop-1-en-1-yl]-4,4-dimethyl-5-phenyl-4,5-dihydro-1,3-thiazole is [M — H]+. Pleiades Publishing, Ltd., 2015 Klyba L. Favorskii Irkutsk Institute of Chemistry, Siberian Branch, Russian Academy of Sciences, ul. Favorskogo 1, 664033, Irkutsk, Russia aut Nedolya N. Favorskii Irkutsk Institute of Chemistry, Siberian Branch, Russian Academy of Sciences, ul. Favorskogo 1, 664033, Irkutsk, Russia aut Tarasova O. Favorskii Irkutsk Institute of Chemistry, Siberian Branch, Russian Academy of Sciences, ul. Favorskogo 1, 664033, Irkutsk, Russia aut Sanzheeva E. Favorskii Irkutsk Institute of Chemistry, Siberian Branch, Russian Academy of Sciences, ul. Favorskogo 1, 664033, Irkutsk, Russia aut Russian Journal of Organic Chemistry Pleiades Publishing 51/4(2015-04-01), 541-551 1070-4280 51:4<541 2015 51 11178 https://doi.org/10.1134/S1070428015040144 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1134/S1070428015040144 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Klyba L. Favorskii Irkutsk Institute of Chemistry, Siberian Branch, Russian Academy of Sciences, ul. Favorskogo 1, 664033, Irkutsk, Russia aut NATIONALLICENCE 700 1- Nedolya N. Favorskii Irkutsk Institute of Chemistry, Siberian Branch, Russian Academy of Sciences, ul. Favorskogo 1, 664033, Irkutsk, Russia aut NATIONALLICENCE 700 1- Tarasova O. Favorskii Irkutsk Institute of Chemistry, Siberian Branch, Russian Academy of Sciences, ul. Favorskogo 1, 664033, Irkutsk, Russia aut NATIONALLICENCE 700 1- Sanzheeva E. Favorskii Irkutsk Institute of Chemistry, Siberian Branch, Russian Academy of Sciences, ul. Favorskogo 1, 664033, Irkutsk, Russia aut NATIONALLICENCE 773 0- Russian Journal of Organic Chemistry Pleiades Publishing 51/4(2015-04-01), 541-551 1070-4280 51:4<541 2015 51 11178