Abstract
A series of 1,4-di[2-aryl-1-diazenyl]-trans-2,5-dimethylpiperazines(5a-5m), have been synthesized by the reaction of trans-2,5-dimethylpiperazine with two equivalents of the appropriate diazonium salt. The products have been characterized by IR and NMR spectroscopy, and the molecular composition has been verified by high-resolution EI mass spectrometry with accurate mass measurement of the molecular ion. The presence of stereocenters at C2 and C5 of the piperazine ring in the bis-triazene (5) creates two unique pairs of diastereotopic protons in the methylene groups at positions 3 and 6 of the piperazine ring, as evidenced by the complexity of the NMR spectra, which nevertheless can be fully assigned in some cases, such as the anisyl-(5i) and phenyl-(5j) derivatives. The assignment of the proton and carbon signals in the tolyl-derivative (5h) has been aided by the use of 2D NMR HSQC spectroscopy. These results compare favorably with assignments of proton and carbon signals reported previously for triazenes of type 1 and bis-triazenes of types 3 and 4b.
| Original language | English |
|---|---|
| Pages (from-to) | 665-669 |
| Number of pages | 5 |
| Journal | Canadian Journal of Chemistry |
| Volume | 92 |
| Issue number | 7 |
| DOIs | |
| Publication status | Published - 22 May 2014 |
| Externally published | Yes |
Keywords
- 2D NMR HSQC spectroscopy
- Bis-triazenes
- Diastereotopic relationships
- Diazonium salts
- Dimethylpiperazine
- IR spectroscopy
- Mass spectrometry
- NMR spectroscopy
- Piperazine
- Triazene
Cite this
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Triazene derivatives of (1, x)-diazacycloalkanes. Part X. Synthesis and characterization of a series of 1,4-di[2-aryl-1-diazenyl]- trans -2,5-dimethylpiperazines. / Little, Vanessa Renee; Tingley, Reid; Vaughan, Keith.
In: Canadian Journal of Chemistry, Vol. 92, No. 7, 22.05.2014, p. 665-669.Research output: Contribution to journal › Article › Research › peer-review
TY - JOUR
T1 - Triazene derivatives of (1, x)-diazacycloalkanes. Part X. Synthesis and characterization of a series of 1,4-di[2-aryl-1-diazenyl]- trans -2,5-dimethylpiperazines
AU - Little, Vanessa Renee
AU - Tingley, Reid
AU - Vaughan, Keith
PY - 2014/5/22
Y1 - 2014/5/22
N2 - A series of 1,4-di[2-aryl-1-diazenyl]-trans-2,5-dimethylpiperazines(5a-5m), have been synthesized by the reaction of trans-2,5-dimethylpiperazine with two equivalents of the appropriate diazonium salt. The products have been characterized by IR and NMR spectroscopy, and the molecular composition has been verified by high-resolution EI mass spectrometry with accurate mass measurement of the molecular ion. The presence of stereocenters at C2 and C5 of the piperazine ring in the bis-triazene (5) creates two unique pairs of diastereotopic protons in the methylene groups at positions 3 and 6 of the piperazine ring, as evidenced by the complexity of the NMR spectra, which nevertheless can be fully assigned in some cases, such as the anisyl-(5i) and phenyl-(5j) derivatives. The assignment of the proton and carbon signals in the tolyl-derivative (5h) has been aided by the use of 2D NMR HSQC spectroscopy. These results compare favorably with assignments of proton and carbon signals reported previously for triazenes of type 1 and bis-triazenes of types 3 and 4b.
AB - A series of 1,4-di[2-aryl-1-diazenyl]-trans-2,5-dimethylpiperazines(5a-5m), have been synthesized by the reaction of trans-2,5-dimethylpiperazine with two equivalents of the appropriate diazonium salt. The products have been characterized by IR and NMR spectroscopy, and the molecular composition has been verified by high-resolution EI mass spectrometry with accurate mass measurement of the molecular ion. The presence of stereocenters at C2 and C5 of the piperazine ring in the bis-triazene (5) creates two unique pairs of diastereotopic protons in the methylene groups at positions 3 and 6 of the piperazine ring, as evidenced by the complexity of the NMR spectra, which nevertheless can be fully assigned in some cases, such as the anisyl-(5i) and phenyl-(5j) derivatives. The assignment of the proton and carbon signals in the tolyl-derivative (5h) has been aided by the use of 2D NMR HSQC spectroscopy. These results compare favorably with assignments of proton and carbon signals reported previously for triazenes of type 1 and bis-triazenes of types 3 and 4b.
KW - 2D NMR HSQC spectroscopy
KW - Bis-triazenes
KW - Diastereotopic relationships
KW - Diazonium salts
KW - Dimethylpiperazine
KW - IR spectroscopy
KW - Mass spectrometry
KW - NMR spectroscopy
KW - Piperazine
KW - Triazene
UR - http://www.scopus.com/inward/record.url?scp=84929147974&partnerID=8YFLogxK
U2 - 10.1139/cjc-2014-0107
DO - 10.1139/cjc-2014-0107
M3 - Article
AN - SCOPUS:84929147974
VL - 92
SP - 665
EP - 669
JO - Canadian Journal of Chemistry
JF - Canadian Journal of Chemistry
SN - 0008-4042
IS - 7
ER -