No abstract

A continuous flow tubing reactor can be used to readily transform methyl or ethyl carboxylic esters into the corresponding hydroxamic acids. Flow rate, reactor volume, and temperature were optimized for the preparation of a small collection of hydroxamic acids. Synthetic advantages were identified as an increased reaction rate and higher product purity. This method was also successfully applied to the multistep preparation of suberoylanilide hydroxamic acid, a potent HDAC inhibitor used in anticancer therapy.

The present work describes the development of an improved synthesis of active pharmaceutical ingredient raltegravir. The isolation of a new process intermediate and the newly developed conditions solve the issue of selectivity typical of this production process, with no need for the use of protecting groups, making the present route more efficient and sustainable than what was reported before. Efficiency comparisons with the previous processes confirm the result here obtained.

Self‐standing chiral electroactive synthetic membranes are presented, prepared by oxidative electro‐oligomerization of a thiophene‐based “inherently chiral” electroactive monomer on indium tin oxide (ITO) or fluorine‐doped tin oxide (FTO) electrodes, followed by detachment of the electrodeposited thin films in aqueous solution. The membranes, possibly mesoporous, consist of a mixture of open and cyclic “inherently chiral” oligomers, that is, in which both chirality and electroactivity originate from the same source, and this is the main conjugated backbone featuring a tailored torsion. Such a combination can afford outstanding chirality manifestations. The electrosynthesis conditions significantly modulate the oligomer distribution. Racemate films are compared to enantiopure ones. Circular dichroism confirms that (R)‐ or (S)‐ enantiopure films are obtained, starting from the corresponding (R)‐ or (S)‐ enantiopure monomers. Reliable transmembrane potential readings are obtained in preliminary tests in ion‐selective electrode (ISE)‐like setups, consistent with those predicted considering the membrane features, offering a first step towards extension of the protocol to chiral experiments.

The alkaline hydrolysis of title esters possessing acidic leaving groups follows an E1cB mechanism involving the participation of an "extra extended" p-oxo ketene intermediate. For the hydrolysis of the 2,4-dinitrophenyl ester kinetic data, activation parameters and trapping of the intermediate clearly indicate that the dissociative pathway carries the reaction flux. Break in the Bronsted plot of the apparent second-order rate constants versus the pK(a) of the leaving group suggests that the reaction mechanism changes from E1cB to B(Ac)2 for esters having pK(a) higher than about 6.