Cyclization of N,N-dialkylditiocarbamate and alkylxanthate derivatives of polyhalogenated pyridines in gas and liquid phases

Eur. J. Mass Spectrom. 10, 57–62 (2004)
DOI: 10.1255/ejms.595

Cyclization of N,N-dialkylditiocarbamate and alkylxanthate derivatives of polyhalogenated pyridines in gas and liquid phases

Tatiana Yu. Samguina, Vladislav V. Lobodin, Nadezhda K. Karakhanova and Albert T. Lebedev^*
Organic Chemistry Department, Moscow State University, Leninskie gori 1/3, Moscow 119899, Russia. E-mail: lebedev@org.chem.msu.ru
Aleksey M. Sipyagin
Institute of Problems of Chemical Physics, RAS, Chernogolovka 142432, Russia

ABSTRACT:

The intramolecular cyclization of 31 polyhalogen substituted pyridines containing N,N-dialkyldithiocarbamate or alkylxanthate groups has been compared in reaction in solution with sodiumN,N-dialkyldithiocarbamates or potassium carbetoxydithiolate and in the gas phase under electron ionization (EI). The scheme of fragmentation of the studied compounds has been proposed. An influence of the nature of leaving groups (Cl, F, CF₃, CN, COOEt), of the presence of electron withdrawing groups (Cl, F, CN, CCl₃, CF₃, COOEt) in ortho-,meta or para-positions to the leaving halogen, of the position of a dithio group toward pyridine nitrogen atom and of the role of oxygen and nitrogen in corresponding alkylxanthates and N,N-dialkyldithiocarbamates on the cyclization process has been investigated.

Keywords: derivatives of polyhalogenated pyridines, electron ionization, cyclization in the gas phase

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