1,3-Dipolar Cycloaddition Reactions in Heterocyclic Synthesis. Synthesis of [1-[4-(thiazolyl/imidazothiazolyl/triazolyl)phenyl]-1H-pyrazole-3,4-dicarboxylate esters from 3-(4-acetylphenyl)sydnone
2005 ◽
Vol 2005
(9)
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pp. 592-594
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Keyword(s):
Cycloaddition of 3-(4-acetylphenyl)sydnone (1) with DMAD gave dimethyl 1-(4-acetylphenyl)-1H-pyrazole-3,4-dicarboxylate (2), which on bromination yielded the corresponding monobromoacetyl (3) and dibromoacetyl (4) derivatives. Both compounds 3 and 4 on reaction with thiourea and thioacetamide afforded the 2-amino- (5) and the 2-methyl- (6) thiazole derivatives respectively, while compound 3 on reaction with 2-aminothiazole gave the imidazothiazole 7. Compound 3 was converted into its azide (8), which on 1,3-dipolar cycloaddition with DMAD afforded the 1,2,3-triazole-4,5-dicarboxylate (9).
2013 ◽
Vol 17
(18)
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pp. 1929-1956
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2013 ◽
Vol 10
(3)
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pp. 481-485
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2002 ◽
Vol 67
(3)
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pp. 353-364
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2001 ◽
Vol 70
(8)
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pp. 641-653
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Keyword(s):