In:
Zeitschrift für Naturforschung B, Walter de Gruyter GmbH, Vol. 69, No. 9-10 ( 2014-10-1), p. 950-964
Abstract:
Introduction of sulfur into the 5-position of 1,4-disubstituted quaternary 1,2,4-triazolium salts (1-9; Cl, Br, I, BF 4 , PF 6 , CH 3 OSO 3 were used as anions) by two methods was investigated. The syntheses of nine 1,4-disubstituted 1,2,4-triazoline-5-thiones 10-18 are reported (1, 10: R 1 = CH 3 , R 2 = CH 3 ; 2, 11: R 1 = NH 2 , R 2 = CH 3 ; 3, 12: R 1 = NH 2 , R 2 = CH(CH 3 ) 2 ; 4, 13: R 1 = N(CH 3 ) 2 , R 2 = CH 3 ; 5, 14: R 1 = N(CH 3 ) 2 , R 2 = CH(CH 3 ) 2 ; 6, 15: R 1 = CH 3 , R 2 = NH 2 ; 7, 16: R 1 = OCH 2 Ph, R 2 = CH 3 ; 8, 17: R 1 = OCH 2 Ph, R 2 = CH 2 CH 3 ; 9, 18: R 1 = CH 3 , R 2 = CH 2 Ph). Compounds 11-17 represent 1-amino, 4-amino, 4-dimethylamino, and 4-benzyloxy-1,2,4-triazoline-5- thiones, whereas 10 served as a reference compound. Thione 18 was identified as an unexpected by-product in the synthesis of 16 and was also prepared independently. Thermolysis of 10 in air gave 1,4-dimethyl-1,2,4-triazolium hydrogensulfate. Crystal structures of eight 1,4-disubstituted 1,2,4- triazoline-5-thiones were determined by single-crystal X-ray diffraction. Intermolecular hydrogen bonds (C-H···S, C-H···N, N-H···N, N-H···S) were observed in the solid state. The solvent-dependent 1 H NMR chemical shifts of signals of 10 and 13 were satisfactorily correlated with the Kamlet- Abboud-Taft π* and b parameters in ten solvents. From the lack of correlation with the a parameter and from the C=S bond length (average 1.67 Å) a significant contribution of a mesoionic imidazolium-2-thiolate resonance structure seems unlikely
Type of Medium:
Online Resource
ISSN:
1865-7117
,
0932-0776
DOI:
10.5560/znb.2014-4145
Language:
English
Publisher:
Walter de Gruyter GmbH
Publication Date:
2014
detail.hit.zdb_id:
2078109-X
detail.hit.zdb_id:
124635-5
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