الفهرس 
Chapter 1: General PartOnly 14 pages are availabe for public view
 |  | from | 252 |  |  |
| | | from | 252 | | |
Abstract
Synthesis of pyrazolo[1,5-a]pyrimidine derivatives with expected biological activities :- This work investigates the facial synthesis and utility of aminopyrazoles in synthesis of some new pyrazolo[1,5-a]pyrimidine derivatives. All the structures were elucidated on the basis of elemental analyses, spectral data and alternative method synthesis. Biological activities of some synthesized compounds are screened. Treatment of aminopyrazole derivatives 1a-f with each of pentan-2,4-dione, benzoylacetone, ethyl 3-oxobutanoate (or acetoacetanilide) and ethyl benzoylacetate (or benzoylacetanilide) in boiling acetic acid under reflux afforded pyrazolo[1,5-a]pyrimidine derivatives 2a-f, 4a-f, 5a-f and 8a-f respectively (Scheme 1). However, 1a was reacted with diethyl malonate (or acetic anhydride) in boiling acetic acid to give product formulated as 5-acetylamino-3-methylsulfanyl-4-phenylcarbamoyl-1H- pyrazole (9a). Also, the appropriate 1a-f were reacted with 1-cyano-2-arylacrylonitrile derivatives to give pyrazolo[1,5-a]pyrimidines 13a-l, respectively (Scheme 2). Also, compound 14a, which prepared via reaction of 1a with benzaldehyde in sodium ethoxide solution, was reacted with malononitrile in ethanol containing catalytical amount of piperidine gave product identical in all respects (mp., mixed mp. and spectra) with 13a. In contrast, treatment of 1a with the appropriate of ethyl 2-aryl-1-cyanoacrylate (15a) in boiling ethanol containing catalytical amount of piperidine afforded shif base 14a (Scheme 3). Finally, treatment of 5-amino-3-methylsulfanyl-4-phenylcarbamoyl-1H-pyrazole (1a) with sodium (2-oxocycloalkylidine)methenolate (19a) in acetic acid containing piperidine acetate afforded a product formulated cycloalkane ring-fused 2-methylthiopyrazolo[1,5-a]pyrimidin-3-carboxamide (22a) (Scheme 4).