Sh. N. Ibragimov

Effect of the Catalyst Nature on the Structure of Products of the Reaction of 4-(Dibromomethyl)Benzaldehyde with Trialkyl Orthoformates

Reactions of 4-(dibromomethyl)benzaldehyde with trialkyl orthoformates in the presence of both Brønsted (H2SO4) and Lewis (ZnCl2) acids involved acetalization of the aldehyde group. In the first case, the corresponding acetal is formed as the only product, whereas in the second case the reaction is accompanied by transformation of the dibromomethyl group to give terephthalaldehyde and its mono- and bis-acetals.

Synthesis of functionally substituted benzaldehydes

A new method of synthesis of functionally substituted benzaldehydes by catalytic debromometoxylation of dibromomethylarenes with benzaldehyde dimethyl acetal has been suggested. Anhydrous zinc chloride has been used as a catalyst. Being soft Lewis acid, it formed no strong complex with aldehyde group and other functional groups. The initial acetal has been readily recovered by the treatment of benzaldehyde isolated from the reaction mixture with trimethyl orthoformate.

Transformation of 4-nitrobenzyl halides at the action of phosphinates and carboxylic acids orthoesters

Previously we studied the reaction of organic gemdiand trihalides with methyl esters of P(IV) acids [1] and trialkyl orthoformates [2]. However, the literature contains no information on the reaction of the above reagents with organic monohalides. We first discovered that methyl diethylphosphinate II reacts with halides Ia and Ib at 150 and 180°C, respectively, to form 4-nitrobenzyl diethylphosphinate IV. Apparently, the phosphinate II attacks the methylene carbon of halide I by its more nucleophilic phosphoryl oxygen. The resulting quasiphosphonium salt III can be stabilized via the second stage of the Arbuzov reaction to release methyl halide V and to form a stable phosphinate IV. DOI: 10.1134/S1070363211070280