METHOD FOR OBTAINING OF BENZOATE AND SUBSTITUTED TIN BENZOATES (IV) Russian patent published in 2018 - IPC C07C51/41 C07C63/08 C01G19/00 C07C51/42 C07C205/57 C07C65/10 C07C63/70 C07C65/21 C07C69/157 C07C65/03 C07C229/64 C07C227/18 C07C229/56 C07C229/60 C07C229/58 

FIELD: chemistry.

SUBSTANCE: invention relates to a method for preparation of benzoate and substituted tin benzoates (IV) by direct reaction of tin dioxide with benzoic, salicylic, p-hydroxybenzoic, anisate, anthranilic, p-aminobenzoic, p- and m-nitrobenzoic, phenylanthranilic, m-chlorobenzoic, acetylsalicylic , 5-aminosalicylic and gallic acids in white spirit in a bead mill with a high speed (3,000 rpm) stirrer in the presence of glass beads as a grinding agent. First, the calculated quantities of beads heated to 49-60°C, white spirit and 5% acid excess are loaded as per stoichiometry, mechanical stirring is activated and solution-suspension of acid is prepared at a naturally developing temperature. Then, without stopping of mixing, a calculated amount of tin dioxide is introduced and a process is carried out to prepare carboxylate while monitoring the content of unreacted acid until the amount of excessively charged amount of this reagent is reached. Once this is reached, stirring is stopped, the reactor is disconnected from its slot in the frame, the lid is removed, the remaining reaction mixture is allowed to flow into the housing, the latter is freed from the contents by transferring it to a funnel with a mesh where the grinding agent is separated from the reaction mixture suspension. The grinding agent is returned to the reactor vessel, the bead mill is assembled, a solvent is added and the housing, reactor elements and beads are washed from the remaining reaction mixture, after which the beads are separated again. The reaction mixture suspension is filtered, the filter cake is rinsed with a washing solvent, squeezed, removed from the filter and dried to a constant weight. The ratio of this mass to the theoretical value is determined by the yield of the isolated product. It turned out to be 95±2.5%, which is less than the degree of conversion of dioxide (approaching 100%) due to losses during reactor unloading and during product separation. The filtrates with the washing solvent are returned to the repeated processes.

EFFECT: method allows to obtain products with high yield and selectivity.

3 cl, 3 tbl, 18 ex