title: Synthesis and analgesic activity of some new pyrazoles and triazoles bearing a 6,8-dibromo-2-methylquinazoline moiety.
abstract: 2-(6,8-Dibromo-2-methylquinazolin-4-yloxy)-acetohydrazide (4) was prepared by the reaction of 6,8-dibromo-2-methylbenzo-[d][1,3]oxazin-4-one with formamide to afford quinazolinone 2, followed by alkylation with ethyl chloroacetate to give the ester 3. Treatment of ester 3 with hydrazine hydrate and benzaldehyde afforded 4 and styryl quinazoline 5. The hydrazide was reacted with triethyl orthoformate, acetylacetone and ethyl acetoacetate and benzaldehyde derivatives to afford the corresponding pyrazoles 6, 7, 9 and hydrazone derivatives 10a-c. Cyclization of hydrazones 10a-c with thioglycolic acid afforded the thiazole derivatives 11a-c. Reaction of the hydrazide with isothiocyanate derivatives afforded hydrazinecarbothioamide derivatives 12a-c, which cyclized to triazole-3-thiols and thiadiazoles 13a-c and 14a-c, respectively. Fusion of the hydrazide with phthalimide afforded the annelated compound 1,2,4-triazolo[3,4-a]isoindol-5-one (15). The newly synthesized compounds were characterized by their spectral (IR, ¹H-, ¹³C-NMR) data. Selected compounds were screened for analgesic activity.
authors.affiliation: Department of Chemistry, Faculty of Science, Taif University, Taif 21974, Saudi Arabia. h_saadzag@yahoo.com
authors.forename: Hosam A
authors.initials: HA
authors.lastname: Saad
authors.forename: Nermen A
authors.initials: NA
authors.lastname: Osman
authors.forename: Ahmed H
authors.initials: AH
authors.lastname: Moustafa
mesh_terms: D000700:Analgesics / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D005260:Female; D008297:Male; D051379:Mice; D011720:Pyrazoles / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D011799:Quinazolines / Q000737:chemistry*; D014230:Triazoles / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*
chemical_list: C570758:6,8-dibromo-2-methylquinazoline; D000700:Analgesics; D011720:Pyrazoles; D011799:Quinazolines; D014230:Triazoles