Archives of Pharmacal Research
- Volume 16 Issue 1
- /
- Pages.75-77
- /
- 1993
- /
- 0253-6269(pISSN)
- /
- 1976-3786(eISSN)
Regioselective Synthesis of [1]Benzopyrano [4,3-c]pyrazol-4-(1H)-one and [1]Benzopyrano[3,4-c]pyrazol-4(3H)-one Derivatives
- Hassaneen, Hamdi M. (Department of Chemistry, Faculty of Science, University of Cairo) ;
- Shawali, Ahmad S. (Department of Chemistry, Faculty of Science, University of Cairo) ;
- Algharib, Mohammed S. (Department of Chemistry, Faculty of Science, University of Cairo) ;
- Elwan, Nehal M. (Department of Chemistry, Faculty of Science, University of Cairo)
- Published : 1993.03.01
Abstract
The cycloaddition reaction of N-phenyl-C-cinnamonitrilimine 4 to coumarin leads to the for-mation of 3-styrylbenzopyrano[4,3-c]pyrazole derivative 6, whereas 3-phenylsulfonylcoumarin 9 or 3-bromocoumain 10 or 3-cyanocoumarin 11 gives 1-styrylbenzopyrano[3,4]pyrazole derivative 7. Also, the cycloaddition of 4 to 3-acetylocoumarin 15 and 3-benzoylocumain 16 gives the corresponding dihydropyrano[3,4-c]pyrazole adducts 17 and 18 respectively. Oxidation of 17 and 18 gives 7.