Synthesis, Spectroscopic and Crystal Structure Analysis of N-[imidazolidin-2-ylidene]-5-(thien-2-yl)[1,3,4]thiadiazole-2-amine

Begum, Noor Shahina; Vasundhara, D. E.; Girija, C. R.; Kolavi, Gundurao; Hegde, Vinayak; Khazi, I. M.

doi:10.1007/s10870-007-9211-z

Cited by 4 publications

(1 citation statement)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3) there is no peak indicating an H atom at the bridging N atom; (iii) there are peaks in the difference map indicating that both imidazolidine N atoms are protonated. Additionally a comparison with another ten known solvent-free derivatives of (I) in the Cambridge Structural Database (CSD; Allen, 2002) revealed that all of them show the 2-imino-imidazolidine tautomeric form (Ib) [CSD refcodes ALALEF (Saczewski et al, 2011), GOLNIE (Elssfah et al, 1999a), HIGGOU (Begum & Vasundhara, 2007), HODQOG (Elssfah et al, 1999b), KIBRAO (Koch et al, 1990), LUVPOH (Varga et al, 2003), QIBBOS (Isobe et al, 2000), VOVCUE01 (Schrö der et al, 2003), XERHOS (Kornicka et al, 2006) and ZAYQOF (Dupont et al, 1995)]. Finally, 1 H NMR measurements show that (for the -CH 2 group), instead of two different signals, as would be expected for the asymmetrical 2-aminoimidazoline tautomer (Ia), only one signal appeared, indicating the symmetrical 2-imino-imidazolidine tautomer (Ib).…”

Section: Commentmentioning

confidence: 99%

Tizanidine and tizanidine hydrochloride: on the correct tautomeric form of tizanidine

Bekö¹,

Thoms²,

Schmidt³

et al. 2011

Acta Crystallogr C

View full text Add to dashboard Cite

A crystallization series of tizanidine hydrochloride, used as a muscle relaxant for spasticity acting centrally as an α(2)-adrenergic agonist, yielded single crystals of the free base and the hydrochloride salt. The crystal structures of tizanidine [systematic name: 5-chloro-N-(imidazolidin-2-ylidene)-2,1,3-benzothiadiazol-4-amine], C(9)H(8)ClN(5)S, (I), and tizanidine hydrochloride {systematic name: 2-[(5-chloro-2,1,3-benzothiadiazol-4-yl)amino]imidazolidinium chloride}, C(9)H(9)ClN(5)S(+)·Cl(-), (II), have been determined. Tizanidine crystallizes with two almost identical molecules in the asymmetric unit (r.m.s. deviation = 0.179 Å for all non-H atoms). The molecules are connected by N-H···N hydrogen bonds forming chains running along [2 ̅11]. The present structure determination corrects the structure determination of tizanidine by John et al. [Acta Cryst. (2011), E67, o838-o839], which shows an incorrect tautomeric form. Tizanidine does not crystallize as the usually drawn 2-amino-imidazoline tautomer, but as the 2-imino-imidazolidine tautomer. This tautomer is present in solution as well, as shown by (1)H NMR analysis. In tizanidine hydrochloride, cations and anions are connected by N-H···Cl hydrogen bonds to form layers parallel to (100).

show abstract

Section: Commentmentioning

confidence: 99%

Tizanidine and tizanidine hydrochloride: on the correct tautomeric form of tizanidine

Bekö¹,

Thoms²,

Schmidt³

et al. 2011

Acta Crystallogr C

View full text Add to dashboard Cite

show abstract

Synthesis and crystal structure analysis of 2-(4-fluorobenzyl)-6-phenylimidazo[2,1-b][1,3,4]thiadiazole and its chlorophenyl derivative

Banu

Lamani

Khazi

et al. 2014

Journal of Saudi Chemical Society

View full text Add to dashboard Cite

Mild and convenient one-pot synthesis of 2-amino-1,3,4-thiadiazoles using trimethylsilyl isothiocyanate (TMSNCS)

2013

View full text Add to dashboard Cite

A novel and efficient one-pot method has been developed for the synthesis of 2-amino-1,3,4-thiadiazoles using various carboxylic acid hydrazides with trimethylsilyl isothiocyanate (TMSNCS). In situ preparation of various thiosemicarbazides by the reaction of different carboxylic acid hydrazides with trimethylsilyl isothiocyanate (TMSNCS), followed by cyclodehydration of thiosemicarbazides under acidic conditions gave 2-amino-1,3,4-thiadiazoles in high yields (71-87%).

show abstract

Synthesis, Spectroscopic and Crystal Structure Analysis of N-[imidazolidin-2-ylidene]-5-(thien-2-yl)[1,3,4]thiadiazole-2-amine

Cited by 4 publications

References 8 publications

Tizanidine and tizanidine hydrochloride: on the correct tautomeric form of tizanidine

Tizanidine and tizanidine hydrochloride: on the correct tautomeric form of tizanidine

Synthesis and crystal structure analysis of 2-(4-fluorobenzyl)-6-phenylimidazo[2,1-b][1,3,4]thiadiazole and its chlorophenyl derivative

Mild and convenient one-pot synthesis of 2-amino-1,3,4-thiadiazoles using trimethylsilyl isothiocyanate (TMSNCS)

Contact Info

Product

Resources

About