6-Amino-5-cyano-1H,4H-pyrazolo[3,4-b]pyrans

Synthesis of Novel Fused Heterocycles Based on Pyrano[2,3-c]pyrazole

“…On the other hand, compound 2 was prepared by the reaction of 6-amino-5-cyano-1,4-dihydro-3-methyl-1-phenyl-4 (p-chlorophenyl) pyrano [2,3-c] pyrazole (1) [11,12] with an equimolar amount of triethyl orthoformate and acetic anhydride [9,10] [1,5-c] pyrimidine (9) was produced. Compound 9 was also produced via the reaction of 3 with acetic anhydride (10) as carboxylic acid anhydride and acetyl chloride (11) as acid chloride.…”

Utility of Enaminonitriles in Heterocyclic Synthesis: Synthesis and Antimicrobial Activity of Some New Azole and Azine Derivatives

“…The starting 6-amino-3-methyl-1,4-diphenyl-1,4-dihydropyrano-[2,3-c]p yrazole-5-carbonitrile (1) was prepared according to the previously reported methods [13,14]. It is well known that, activation of cyanoacetic acid by conversion to the mixed anhydride with acetic anhydride has been used [15][16][17][18] but the generality, simplicity and usefulness has not been appreciated and the reagent has infrequently been used for N-acetylations of e.g.…”

Green Approach to the Design of Functionalized Medicinally Privileged 4‐Aryl‐1,4‐dihydropyrano[2,3‐c]‐pyrazole‐5‐carbonitrile Scaffold

“…The methods of pyrano[2,3‐ c ]pyrazoles synthesis have long been documented and consist of two main groups: (1) two‐step synthesis and (2) “one‐pot” multicomponent condensation. The reaction of aromatic aldehydes, malononitrile, and 3‐methyl‐2‐pyrazoline‐5‐one is well known and most efficient way to pyrano[2,3‐ c ]pyrazoles . This multicomponent process includes Knoevenagel condensation of aromatic aldehyde and malononitrile, Michael reaction of formed Knoevenagel adduct with 3‐methyl‐2‐pyrazolin‐5‐one, and final cyclization step to appropriate pyrano[2,3‐ c ]pyrazole.…”