A Novel Approach in Cinnamic Acid Synthesis: Direct Synthesis of Cinnamic Acids from Aromatic Aldehydes and Aliphatic Carboxylic Acids in the Presence of Boron Tribromide

Abstract

Cinnamic acids have been prepared in moderate to high yields by a new direct synthesis using aromatic aldehydes and aliphatic carboxylic acids, in the presence of boron tribromide as reagent, 4-dimethylaminopyridine (4-DMAP) and pyridine (Py) as bases and N-methyl-2-pyrolidinone (NMP) as solvent, at reflux (180-190°C) for 8-12 hours.

Synthesis and characterization of two novel biological-based nano organo solid acids with urea moiety and their catalytic applications in the synthesis of 4,4′-(arylmethylene)bis(1H-pyrazol-5-ol), coumarin-3-carboxylic acid and cinnamic acid derivatives under mild and green conditions

“…In the surface conformation of the coat, 2-carbamoylhydrazine-1sulfonic acid nano structure organocatalyst with a size less than 65 nm were detected clearly. 45 The UV/Vis absorbance spectrum of the nano structure organocatalyst was compared with those of reactants and reaction mixture to highlight the distinction between the UV/Vis absorbance pattern of the catalyst, reactants and reaction mixture. As revealed in Fig …”

“…To compare the effect of the solution in comparison with solvent-free conditions, a mixture of 4chlorobenzaldehyde and 1-phenyl-3-methylpyrazol-5-one 30 as model reaction, in the presence of 10 mol% of nano organocatalysts in several solvents such as C 2 H 5 OH, CH 3 CN, CH 3 CO 2 Et and toluene were studied at 60 o C. Solvent-free condition was the best condition in this reaction. 35 After optimization of the reaction conditions, to study the efficacy and the scope of the offered process, several of 4,4'-(arylmethylene)bis(1H-pyrazol-5-ol) derivatives were 40 produced via the condensation reaction between aromatic aldehydes and 1-phenyl-3-methylpyrazol-5-one in the presence of catalytic amounts of 2-carbamoylhydrazine-1sulfonic acid and carbamoylsulfamic acid as nano structure organocatalysts under solvent-free reaction 45 conditions. The results have been represented in Table 4.…”

“…This advanced extension well-known as 'green Chemistry' or 'sustainable development' requires a model shift from common contents of method efficacy, 40 that attention mainly on yield of product, to one that gives economic value, removing waste and avoiding the usage of toxic or dangerous materials. 1-3 Furthermore the significant properties seen in water as an effect of its chemical and physical properties are very beneficial for 45 selectivity and reactivity that cannot be achieved in other organic solvents and make it an efficient solvent for many organic reactions, not just for biochemical procedures. 4,5 In the field of organic chemistry for example nucleoside, peptide or combinatorial synthesis, simply available amine 50 protecting groups are frequently needed, which are stable under a wide range of reaction conditions and are simply and selectively cleavable.…”

“…After 40 completion of the reaction which was observed via TLC (n-hexane/ethyl acetate: 5/2), the mixture washed with water and separated of nano organocatalyst, the solid product purified by recrystallization from ethanol. All of the desired product(s) were characterized by comparison 45 of their physical data with those of known compounds. General procedure for the preparation of coumarin-3carboxylic acid derivatives.…”

Glycerol Containing Triacetylborate Mediated Syntheses of Novel 2-Heterostyryl Benzimidazole Derivatives: A Green Approach

“…Triacetylborate is prepared according to the reported procedure [18], which is soluble in glycerol, maintaining the optimum acidity of the reaction medium and at the same time it is not necessary to use acids like H 2 SO 4 or HCl and oxalic acid to prepare salts or to recover the product during the work-up process. Both triacetylborate and glycerol, being highly soluble in water, can be recycled after the reaction.…”