sydnone chemistry and microwave assisted synthesis of sydnonyl-substituted imidazoles (i)
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Sydnone Chemistry and Microwave Assisted Synthesis of Sydnonyl-Substituted Imidazoles (I). Mei-Hsiu Shih Department of Chemical and Material Engineerin g Southern Taiwan University of Technology. Outline. (Ⅰ) Introduction of sydnone chemistry (Ⅱ) Sydnonyl-substituted pyrazolines - PowerPoint PPT PresentationTRANSCRIPT
Sydnone Chemistry and Microwave Assisted Synthesis of Sydnonyl-Substituted Imidaz
oles (I)
Mei-Hsiu Shih
Department of Chemical and Material EngineeringSouthern Taiwan University of Technology
Outline
( ) Introduction of sydnone chemistryⅠ
( ) Sydnonyl-substituted pyrazolinesⅡ
( ) Thiadiazoline and thiadiazole derivativesⅢ
( ) Microwave assisted synthesis of sydnonyl- Ⅳ substituted imidazoles
( ) Introduction of sydnonesⅠ
(A) Background
Sydnone was first discovered by Earl and Mackney in 1935.
They obtained a five-membered cyclic compound by the action of acetic anhydride on N-nitro-N-phenylglycine.
Electronic structure and varied types of biological activity.
N
NO
CH2 CO
OH
N
ON
H
O
(CH3CO)2O
H2O_
1 2
1
2
3 4
5
(M)
O
R'R
NO
N
N
ON
R'
O
R N
ON
R'
O
R
(A) (B)
(B) General synthetic procedure
Sydnones were generally prepared by the action of certain dehydrating agents, notably acetic anhydride, on the N-nitroso derivatives of N-substituted α–amino acids.
NHR CHOH
OC
R'
+ NaNO2 N CHOH
OC
R'
R
NO
cyclization N
ON
R R'
O
5
4
3
(C) Physical and chemical properities
Tetrahedron, 2002, December, 58, 10437-10445.Tetrahedron, 2003, June, 59, 4103-4111.Bioorganic & Medicinal Chemistry, 2004, September, 12, 4633-4643Synthesis, 2004, December, 17, 2877-2885.
N
ON
O
RN
ON
R'
O
(D) Biological activity
(E) Syntheses of 4-heterocyclic substituted sydnones