SU525681A1 - The method of obtaining 1,4-diazabicyclo / 2,2,2 / octane - Google Patents

Description

The invention of ognosigs to improve the method of producing diazabicyclo (2.2.2 octane, which is widely used as an effective catalyst in the manufacture of polyurethane foams, especially flexible and solid polyurethane foams, in the polymerization of olefins, formaldehyde, etc., during curing of epoxy resins and polyacrylate rubbers, dyeing textiles with reactive dyes, etc.

Methods are known for preparing 1,4-diazabicyclo (2,2,2) octane or triethylenediamine (TEDA) by catalytic conversion of various amines (linear or cyclic) on cracking aluminosilicate catalysts, alumina with various additives, tungsten oxide, and metal phosphates at temperatures 220500 ° C, pressure 0.1-150 at, in the presence of various diluents. Thus, on aluminosilicate catalysts, the yield of triethylenediamine from M-amino ethyl piperazine reaches 35% of the theoretically calculated reacted N α-amino ethyl piperazine. By passing a mixture consisting of α-bisoxyethylpiperazine and 60% monooxyethylpiperazine over an aluminosilicate catalyst at a temperature of 350-360 0 and a space velocity of 0.44 hours, a yield of 64% was obtained from the theoretically calculated conversion of 87.8%. As a catalyst for the preparation of triethylenediamine, various metal phosphates are used at a temperature of 250-550 ° C. Thus, on calcium phosphate, at a temperature of 38 ° C and atmospheric pressure, 27% molar triethylenediamine is obtained from M-aminoethylpiperazine, and on aluminum phosphate at 375 ° C, the yield is 39% molar. The feedstock may contain up to 50% water. When contacted with aluminum phosphate at a temperature of 40 ° C, N-oxyethylpiperazine gives only 33% by weight. triethylenediamine.

The main disadvantage of the known methods is the low selectivity of the process and the relatively low yield of the target product. In order to increase product yield and increase selectivity, as well as simplify the process due to the separation stage, a solid single or polyphase calcium phosphate catalyst is used as a phosphate catalyst, which has a certain hydroxylapite titanium lattice with a Cr, 0 molar ratio (P, 0 equal to 2.6-3.0. The catalyst consists mainly of calcium-hydroxylapatite, prepared from calcium salts and phosphoric acid, has a specific surface area of 40-160 m / g (argon), preferably with a total pore volume of not less than e 0.3 ml / g, amorphous phase - acid phosphates. It has sufficient mechanical strength, is able to regenerate and work in the presence of large quantities of water. Mono- or disubstituted piperazines can be used as a feedstock, with the general formula: .24 CH or alkylene polyamines of the general formula. / -NH- (CH, Crt ,, m; - X, Where X is MN., OI,, n 1-4, as well as alkanolamines, for example, N-amino ethyl piperazine, N, N1-bis { aminostyl) piperazine, diethylene triamine triethylene tetramine, tetraethylene peptamine or mixtures thereof, N-hydroxy ethyl piperazine. N, N-bis (hydroxyethyl) piperazine, ethoxylated polyethylene polyamines (ethylenediamine, diethylenetriamine, etc.) monoethanolamine, diethanolamine, or mixtures of these products. The process can be conducted both continuously and periodically, at atmospheric, elevated or reduced pressure. The reaction can be carried out in the presence of a diluent of liquid and / or gaseous or without it, as well as in the presence of ammonia. Aliphatic and aromatic hydrocarbons, which are not subjected to transformations on catalysts of the mentioned type, or their mixtures, or water, or mixtures of hydrocarbons and water, can be used as a liquid diluent for any concentration of the feedstock. Nitrogen, hydrogen, etc., including ammonia can be used as a gaseous diluent. The introduction of ammonia increases the yield of the target product. EXAMPLE 1. A tubular reactor with 50 ml of a solid catalyst containing 70% of the crystalline phase (having, according to X-ray structural analysis, the structure of a hydroxylapatite and 30% of the x-ray amorphous phase, at atmospheric pressure, continuously passes 0.5 mol / hour of nitrogen and N-aminoethylpiperazine with a space velocity of 0.59 hours at a temperature. According to gas-liquid chromatography, the total conversion of N-amino ethyl piperazine is 98%, and conversion to triethylenediamine is about 50% molar and 36% molar piperazine. types of initial products - according to examples 1-12 are given in the table.

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Claims (1)

9 claims The method of obtaining 1,4-diazabicyclo (2,2, 2) octane by heating mono- or disubstituted piperazines, or ethylene polyamines, or products of their oxyethylation, or alkanolamines or their mixtures to a temperature of 200-550 ° C under pressure up to 100 atm in the presence of a phosphate catalyst, followed by separation of the ce525681 ten left product, characterized in that, in order to increase the yield of the target product and simplify the process, a solid single or polyphasic calcium phosphate catalyst with a molar ratio CaO / P Oy equal to 2.6-3.0, with a specific surface area is taken as a phosphate catalyst . 40-160 m / g, with a total pore volume of at least 0.3 cm / g, containing as the main component a phase with a hydroxylapatite crystal lattice