Machado, Antonio S.; de Carvalho, Flavio S.; Mouraa, Rayssa B. P.; Chaves, Lorrayne S.; Liao, Luciano M.; Sanz, German; Vaz, Boniek G.; Rodrigues, Marcella F.; Romao, Wanderson; Menegatti, Ricardo; Silva, Gloria N. S. published the artcile< Comparison of Conventional and Microwave Synthesis of Phenyl-1H-pyrazoles and Phenyl-1H-pyrazoles-4-carboxylic Acid Derivatives>, Name: 1-(4-Bromophenyl)-1H-pyrazole, the main research area is carboxylic acid phenyl pyrazole preparation green chem microwave irradiation; carbaldehyde phenyl pyrazole oxidation; phenyl pyrazole preparation green chem microwave irradiation; phenylhydrazine tetramethoxypropane heterocyclization; Pyrazole; conventional heating; heterocycle; microwave irradiation.; privileged scaffolds; synthesis.
The purpose of this study was the optimization of the conventional synthesis of the pyrazole rings I (R1 = H) and the oxidation of phenyl-1H-pyrazole-4-carbaldehydes I (R = H, 2-Cl, 3-Br, 4-CF3, etc.; R1 = CHO) to phenyl-1H-pyrazole-4-carboxylic acids I (R1 = COOH) through Microwave- Assisted Organic Synthesis (MAOS). A comparison between conventional synthesis and conventional synthesis with microwave heating using the synthesis method of pyrazole ring described by Finar and Godfrey and for the oxidation of phenyl-1H-pyrazole-4-carbaldehyde, and the method described by Shriner and Kleiderer was used. MAOS reduces the reaction time to obtain all compounds compared to conventional heating. At a temperature of 60°C, 5 min of reaction time, and power of 50 W, the yield of phenyl-1H-pyrazoles I (R1 = H) was in the range of 91 – 98% using MAOS, which is better than conventional heating (72 – 90%, 75°C, 2 h). An improvement in the yield for the oxidation reaction was also achieved with MAOS. The compounds I (R1 = COOH) were obtained with yields ranging from 62 – 92% (80°C, 2 min, 150 W), while the yields with conventional heating were in the range of 48 – 85% (80°C, 1 h). The 26 compounds I were achieved through an easy work-up procedure with no chromatog. separation
Current Organic Synthesis published new progress about Aromatic carboxylic acids Role: SPN (Synthetic Preparation), PREP (Preparation). 13788-92-6 belongs to class pyrazoles-derivatives, and the molecular formula is C9H7BrN2, Name: 1-(4-Bromophenyl)-1H-pyrazole.
Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics