2250-60-4Relevant academic research and scientific papers
Controlled photo-flow oxidative reaction (UV-FOR) platform for ultra-fast phthalide and API synthesis
Aand, Dnyaneshwar,Karekar, Sanjeev,Mahajan, Bhushan,Pawar, Amit B.,Singh, Ajay K.
, p. 4584 - 4590 (2018/10/23)
An integrated photo-flow oxidative reaction (UV-FOR) platform approach is presented for the synthesis of phthalides. The current protocol is catalyst-free, and uses economical and abundant hydro-carbons and hydrocarbon derivatives such as benzoic acid, benzene, and xylene, as starting materials. The reaction is performed using oxygen as a green oxidant in a time- and labour-efficient manner. This integrated approach has been shown to be successful in making a UV-FOR platform suitable for the on-demand synthesis of phthalides and their further syntheses to 2-arylmethylbenzoic acids and arylogous Michael addition products under relatively mild conditions. The current protocol was further extended to the gram scale synthesis of an ischemic stroke-relevant active pharmaceutical ingredient (API), 3-N-butylphthalide (NBP), in a continuous flow process.
Friedel-Crafts acylation reaction using carboxylic acids as acylating agents
Kawamura, Masato,Cui, Dong-Mei,Shimada, Shigeru
, p. 9201 - 9209 (2007/10/03)
Dehydrative Friedel-Crafts acylation reaction of aromatic compounds with carboxylic acids as acylating agents was investigated in the presence of Lewis acid- or Br?nsted acid-catalyst. Various metal triflates and bis(trifluoromethanesulfonyl)amides showed catalytic activity at high temperature, among which Eu(NTf2)3 proved to be the most effective and efficiently catalyzed the acylation reaction of alkyl- and alkoxybenzenes with aliphatic and aromatic carboxylic acids at 250 °C. Bi(NTf2)3 was more effective than Eu(NTf2)3 at lower temperature, but proved to be hydrolyzed in the presence of a small amount of water to give HNTf2 and [Bi6O4(OH)4(H2O)6](NTf2)6. The structure of the latter compound was confirmed by a single crystal X-ray analysis. Among five Br?nsted acids, HOTf, HNTf2, HCTf3, TsOH, and Nafion SAC-13, HNTf2 has proved to be the most efficient catalyst and more effective than Eu(NTf2)3 for the acylation of p-xylene with heptanoic acid at 220 °C or lower temperature. HNTf2 catalyzed the acylation of anisole with carboxylic acids in high yields in refluxing toluene with azeotropic removal of water.
