RU2331629C1 - Method of obtaining manganese salicylate (ii) - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention pertains to perfection of the method of obtaining manganese salicylate (II), which can be used as a reagent and catalyst of chemical transformations in laboratory and industrial practicale. The method involves reaction of metallic manganese and its dioxide with acid in the presence of an organic solvent and an iodine stimulating additive in a vertical type bead mill with glass bead as a grinding agent in the absence of supply of external heat. The content of salicylic acid and iodine in the load is 0.8÷2.2 and 0.04÷0.07 mol/kg respectively. Manganese dioxide is taken in molar ratio to the acid of 1: (4.0÷4.2) and 1:(1.9÷2.3) to metal. Mass ratio of the load to the glass beads is 1:1.5. The load is taken in the order glass beads, solvent, acid, stimulating additive, metal and then its dioxide. The process itself is started with mixing and is carried out at room temperature until complete exhaustion of the metal dioxide, after which mixing is stopped. The suspension of the product is separated from the glass beads and particles of unreacted manganese by passing through a filtering partition wall in form of a net with cell dimensions of 0.4÷0.5 mm. The obtained product residue from filtering is washed in liquid solvent, after which it is taken for cleaning by re-crystallisation. The filtrate, washed by the solvent and unreacted metal is returned for a repeated process.

EFFECT: obtaining manganese salicylate with direct reaction with salicylic acid in solutions at room temperature.

2 cl, 1 tbl, 8 ex

Description

The invention relates to a technology for producing manganese salt of salicylic acid, which can be used as reagents and catalysts for a number of chemical transformations in the laboratory and in industrial practice.

A known method of producing manganese salts of substituted salicylic acids (US Patent No. 5306688), in accordance with which the product is obtained by the exchange interaction between the sodium salt of the acid and the water-soluble metal salt.

The disadvantage of this method is that both reagents are not natural substances and require their preliminary preparation. And if the water-soluble salt of manganese is readily available, then it is no longer possible to say so about the sodium salt of the acid.

Closest to the claimed is a method of producing manganese (II) salicylate (patent GB 689629A, publ. 01.04.1953). In accordance with it, 5.3 parts of anhydrous sodium carbonate are dissolved in 100 parts of water, after which 13.8 parts of salicylic acid are dissolved in the resulting solution. This solution is mixed with a solution of manganese sulfate (11.1 parts of crystalline manganese sulfate in 50 parts of water). The mixture is concentrated in vacuo at 20-25 ° C, filtered and dried.

Essentially, this is the same exchange interaction with the only difference being that sodium salt of salicylic acid is not isolated, but its solution is used as a whole. Consequently, the disadvantages are also similar. In particular:

1. In this process, an accompanying product is formed - sodium sulfate, which takes a significant part of the mass of the starting reagents.

2. The number of starting reagents is large: these are sodium carbonate, salicylic acid and manganese sulfate. In this case, the anion of sodium carbonate is converted by interaction with salicylic acid into carbon dioxide, which is removed into the gas phase, which leads, on the one hand, to unproductive loss of a certain part of the mass of the initial reagent, and on the other hand, it requires certain actions and costs to create favorable conditions labor attendants.

3. In the reaction mixture, the main component is water (150 parts versus 13.8 + 5.3 + 11.1 parts of the starting reagents). Thus, the product solution is quite diluted and requires concentration. The selected conditions of the latter (under vacuum at 20-25 ° C) are difficult and time-consuming.

4. The method presents unnecessarily stringent and obscure requirements for the starting reagents. In particular, we are talking about anhydrous sodium carbonate, which is dissolved in water, etc.

The objective of the proposed solution is to obtain manganese (II) salicylate from metallic manganese and its dioxide by direct interaction with salicylic acid in solutions of organic substances at room temperature.

This object is achieved in that they carry out the interaction of manganese metal and its dioxide with salicylic acid in the presence of an organic solvent and a stimulating iodine additive in a vertical type bead mill with glass beads as a grinding agent in the absence of external heat, while the content of salicylic acid and iodine in loading amounts to 0.8 ÷ 2.2 and 0.04 ÷ 0.07 mol / kg, respectively, manganese dioxide is taken in molar ratio with acid 1: (4.0 ÷ 4.2) and with metal 1: (1.9 ÷ 2,3), mass ratio loading and glass beads 1: 1.5, loading is carried out in the following sequence: glass beads, solvent, acid, stimulating additive and then the metal and its dioxide, and the process itself begins with stirring and is carried out at room temperature until the charge is almost completely consumed. dioxide, after which the stirring is stopped, the suspension of the product is separated from glass beads and particles of unreacted manganese by passing through a filter baffle in the form of a mesh with mesh sizes of 0.4 ÷ 0, 5 mm and then filtered, the resulting product precipitate is washed with a small amount of solvent of the liquid phase, after which it is sent for purification by recrystallization, and the filtrate, washing solvent and unreacted metal are returned to the repeated process. In this case, heptane, m-xylene, chlorobenzene, white spirit, and butyl acetate are used as a solvent of the liquid phase.

Characteristics of the raw materials used:

Reactive manganese according to GOST 6008-90

Manganese dioxide according to GOST 4470-79

Crystalline iodine according to GOST 4159-79

Salicylic acid according to GOST 5848-73

Butyl acetate according to GOST 8981-78

Heptane reference (TU 6-09-4520-77)

m-Xylene (TU 6-09-2438)

Chlorobenzene according to GOST 13488-68

White spirit technical in accordance with GOST 3134-78

The process of the claimed method is as follows. Glass beads are introduced into a bead mill of a vertical type with a glass casing, a high-speed mixer made of textolite, teflon or other inert and durable plastic, and equipped with a reflux condenser, a mass ratio of 1.5: 1, liquid solvent, acid, stimulating additive of molecular iodine, metal and its dioxide. Turn on mechanical mixing and this moment is taken as the beginning of the process. During the process, samples of the reaction mixture are taken, in which the contents of salt and salicylic acid, as well as manganese dioxide, are determined. As soon as manganese dioxide is almost completely consumed, stirring is stopped, the reaction mixture is separated from glass beads and the bulk of heavy unreacted manganese particles, after which the suspension of the product is sent for filtration. The precipitate is washed with a solvent of a liquid phase. The filtrate, which is a saturated solution of manganese salicylate in the final liquid phase, is analyzed, mixed with a washing solvent and, together with unreacted metal, is recycled. Salt is sent for purification from impurities by recrystallization.

Example No. 1.

247.5 g glass beads with a diameter of 1.2 ÷ 1.8 mm are loaded into a bead mill with a glass case with an inner diameter of 59 mm and a height of 140 mm with a textolite paddle mixer 0.3 mm from the bottom of the reactor and a reflux condenser and 108 g of butyl acetate. Then, 41.4 g of salicylic acid, 1.9 g of iodine, 7.5 g of metallic manganese and 6.2 g of manganese dioxide are introduced. Turn on mechanical mixing and this moment is taken as the beginning of the process. During the process, samples of the reaction mixture are taken and the current conversion of salicylic acid and manganese dioxide, as well as the salt content in the reaction mixture, are determined by the results of the analysis. After 120 minutes, the degree of conversion of salicylic acid exceeded 96%, and the manganese dioxide in the sample was present in trace amounts. Stirring is stopped, the reaction mass is separated from the beads, passing it through the filter partition in the form of a mesh with hole sizes of ~ 0.4 × 0.5 mm. This operation is performed in such a way that the bulk of the heavy particles of manganese remains at the bottom of the bead mill and on the beads. The salt suspension is filtered. The precipitate was washed with 25 g of butyl acetate. The washing solvent, the filtrate and the unreacted metal are recycled and the resulting salt is recrystallized. The yield of separated and dried product was 93% based on the charged acid.

Examples No. 2-8.

The initial reagents, the nature of the oxide, the mass ratio of the beads and the load, the sequence of operations of the process, monitoring its progress, unloading the final reaction mixture, isolating the solid product and returning the individual components to the repetitive process are similar to those described in Example 1. They differ in the nature of the solvent, salicylic acid content and a stimulant in the charge, in molar ratios of manganese dioxide and acid, as well as manganese dioxide and metal in the charge. The results are summarized in the table (notation: BA - butyl acetate, G - heptane, HB - chlorobenzene; US - white spirit; mK - m-xylene).

Table Characteristics of the loading and salt production process Example No. 2 3 four 5 6 7 8 The content in the load, mol / kg
salicylic acid 1.4 2.0 2.1 1,0 1.3 2.2 0.8 iodine 0.04 0.05 0,07 0,07 0.05 0.05 0.04 Molar ratio manganese dioxide and manganese dioxide 1: 1.9 1: 2,3 1: 2.1 1: 2.0 1: 2.0 1: 2.0 1: 2.0 manganese dioxide and salicylic acid 1: 4.1 1: 4,2 1: 4.0 1: 4.0 1: 4.1 1: 4.1 1: 4.1 Liquid phase solvent BA BA BA HB CSS G mk The duration of the process until termination, min 97 124 131 89 117 157 92 The degree of conversion of acid at the time of termination of the process,% 98 94 98 98 95 96 95 The amount of solid product in% of theoretical at 100% consumption of acid 92 91 95 94 92 93 92

The positive effect of the proposed solution

1. The method is quite simple in execution, does not require external heat supply and is oriented to completely accessible raw materials.

2. The cationic composition of the reaction mixture is simplified. Moreover, for about half of the salt accumulated, the raw material is manganese dioxide, which is a natural compound.

3. The hardware design of the process is simple and does not contain boiler monitoring equipment. This process can be successfully carried out in a low-waste version. Any unwanted inhibitors are not formed and do not accumulate in it, which makes it possible to carry out subsequent series in devices with dead zones and not to lose the reaction mixture for this reason. There are no restrictions on the return of the spent liquid phase and unreacted metal and its oxide to the second process.

4. A fairly simple cleaning of salt from impurities by recrystallization.

Claims (2)

1. A method of producing manganese (II) salicylate, characterized in that the interaction of metallic manganese and its dioxide with an acid in the presence of an organic solvent and a stimulating additive of iodine in a vertical type bead mill with glass beads as a grinding agent in the absence of external heat, when the contents of salicylic acid and iodine in the load are 0.8 ÷ 2.2 and 0.04 ÷ 0.07 mol / kg, respectively, manganese dioxide is taken in a molar ratio with acid 1: (4.0-4.2) and s metal 1: (1.9 ÷ 2.3), mass the ratio of loading to glass beads is 1: 1.5, the loading is carried out in a sequence of glass beads, solvent, acid, a stimulating additive, and then the metal and its dioxide, and the process starts with stirring and is carried out at room temperature until the charged dioxide is almost completely consumed. metal, after which stirring is stopped, the suspension of the product is separated from glass beads and particles of unreacted manganese by passing through a filter baffle in the form of a mesh with mesh sizes the cells 0.4 ÷ 0.5 mm and then filtered, the resulting product precipitate is washed with a small amount of a solvent of the liquid phase, after which it is sent for purification by recrystallization, and the filtrate, washing solvent and unreacted metal are returned to the repeated process. 2. The method according to claim 1, characterized in that heptane, m-xylene, chlorobenzene, white spirit and butyl acetate are used as a solvent for the liquid phase.