Mass spectra of new groups of functionalized heterocycles 3. 3-Alkyl- and 5-alkyl-2-thienylamines

The influence of the position and nature of the substituent in the thiophen e ring on the fragmentation of 3-alkyl- and 5-alkyl-2-thienylamines under e lectron impact was studied. The derivatives containing the ethyl group in p osition 3 decompose due to both the elimination of the fragments from the s ubstituents and thiophene ring rupture. In the case of the compounds with t he tert-butyl group in position 5, the last process is not observed. The fr agmentation of the 3- and 5-methyl-substituted derivatives occurs mainly fr om the isomeric thiopyran form of the molecular ion.