Synthesis of dialkyl 5-(aryl)-1-phenyl-1H-prazole-3,4-dicarboxylates via a one-pot and four-component reaction

Four 1-aryl-1H-pyrazole-3,4-dicarboxylate derivatives: synthesis, molecular conformation and hydrogen bonding

“…In dimethyl 1-(3-chloro-4-methyl)-1H-pyrazole-3,4-dicarboxylate, which differs from (III) only in the presence of the additional 3-chloro substituent, there are again two C-HÁ Á ÁO hydrogen bonds in the structure, involving exactly the same pair of C-H bonds as in (III), but here the molecules are linked into a C(5)C(8)[R 1 2 (7)] chain of rings, rather than into cyclic dimers (Thamotharan et al, 2003). The esters dimethyl 5-(4-chlorophenyl)-1-phenyl-1H-pyrazole-3,4-dicarboxylate (Li et al, 2014) and dimethyl 5-(4-bromophenyl)-1-phenyl-1Hpyrazole-3,4-dicarboxylate (Alizadeh et al, 2010), which carry an additional substituent in the pyrazole ring, are isostructural, and the molecules are linked by C-HÁ Á ÁO hydrogen bonds to form simple chains.…”

One-Pot, Pseudo Five-Component Synthesis of Spirooxindole Derivatives Containing Fused 1,4-Dihydropyridines in Water

“…In continuing efforts to develop new routes for the synthesis of biologically active heterocyclic compounds, [12][13][14][15][16][17][18] a five-component reaction that generates spirooxindole heterocycles is described herein. Thus, the reaction between 1,1-bis(methylthio)-2-nitroethylene, two equivalents of ammonia, isatin or its derivatives 1, and 1,3-dicarbonyl compounds 2 in the presence of 10 mol% p-toluenesulfonic acid (p-TSA) as an inexpensive catalyst in water under reflux conditions afforded a series of spirooxindole derivatives 3 containing 1,4-dihydropyridine-fused 1,3-diazaheterocycle fragments in 75-81% yields ( Table 1).…”

“…MS: m/z (%) = 371 (1) [M + ], 368(12), 311(16), 294(18), 192 (38), 164 (100), 134 (50), 106 (66), 90 (98), 75 (99), 63 (99), 51 (95). Anal.…”