Published in: Journal, Volume : 43, Issue : 45, Pages : 8165-8167
DOI : 10.1016/s0040-4039(02)01956-1
Author : Blass, Benjamin E.; Coburn, Keith R.; Faulkner, Amy L.; Liu, Song; Ogden, Adam; Portlock, David E.; Srivastava, Anil
Abstract : The solid supported synthesis of functionalized 1,2,4-triazin-6-ones from resin bound amino acids and acid chlorides is described. A thioamide intermediate is generated with Lawesson’s reagent, and the final products are cyclized and cleaved from resin with hydrazine. The products are obtained in good yield and purity.
Published in: Journal, Volume : 43, Issue : 38, Pages : 6845-6847
DOI : 10.1016/s0040-4039(02)01511-3
Author : Portlock, David E.; Naskar, Dinabandhu; West, Laura; Li, Min
Abstract : R1CONHNHR2 [R1 = OCMe3, OCH2Ph, NH2; R2 = cyclohexylmethyl, Me2CHCH2, MeO2CCH2, PhCH2, Ph, 4-MeC6H4, 4-O2NC6H4,2-pyridyl, H, EtO2CCH2] can serve as amine substrates for the Petasis boronic acid-Mannich reaction with R3B(OH)2 [R3 = 4-MeOC6H4, 4-MeC6H4, PhCH:CH, Ph, 2-benzothienyl, 1-naphthyl] and OCHCO2H, providing a practical synthetic route for the preparation of α-hydrazinocarboxylic acids R1CONHNR2CHR3CO2H. The scope and limitations of this method have been examined
Published in: Journal, Volume : 45, Issue : 3, Pages : 619-621
DOI : 10.1016/j.tetlet.2003.10.177
Author : Blass, Benjamin E.; Srivastava, Anil; Coburn, Keith R.; Faulkner, Amy L.; Janusz, John J.; Ridgeway, James M.; Seibel, William L.
Abstract : The solution phase synthesis of a series of imidazo[1,2-b]pyrazol-2-ones, e.g., I, a fused 5,5-ring system, is described. The heterocyclization of α-hydrazino acids with α-cyano ketones gave 5-aminopyrazoles, e.g., II, which underwent an intramol. cyclodehydration to give the corresponding imidazo[1,2-b]pyrazol-2-ones.