Crystal structures of the 1:1 salts of 2-amino-4-nitrobenzoate with each of (2-hydroxyethyl)dimethylazanium, tert-butyl(2-hydroxyethyl)azanium and 1,3-dihydroxy-2-(hydroxymethyl)propan-2-aminium

Abstract

Three ammonium salts of 2-amino-4-nitro­benzoate are described. Based on N—H⋯O and O—H⋯O hydrogen-bonding involving the different constituents, supra­molecular chains, tubes and double-layers are found in their crystals.

Deep eutectic solvent as solvent and catalyst: one-pot synthesis of 1,3-dinitropropanesviatandem Henry reaction/Michael addition

“…After the nitroolefin is formed by elimination of water, a possible and cooperative action of both the urea and the choline components of DES can be suggested to explain the high reactivity toward the formation of the 1,3-dinitropropane product. Choline can activate the nitroolefin by coordination involving both the ammonium and the hydroxy group as shown in Scheme 5 (similar mode of interactions has been yet observed in the solid state 39 ).…”

“…Urea-based catalysts are known to work in such reactions by hydrogen bonding catalysis. 39 On the bases of the results previously discussed, a possible mechanism for the formation of the 1,3-dinitropropane derivative can be postulated, as in Scheme 4. The first step, the formation of nitroaldol, occurs through a classical activation of nitromethane by coordination of the nitro group with urea, promoting the reaction and give betanitro alcohol compound (Scheme 4).…”