RU2459803C2 - METHOD OF PRODUCING 4,4'-(m-PHENYLENEDIOXY)DIPHTHALONITRILE - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to chemistry, specifically to an improved method of producing 4,4'-(m-phenylene-dioxy)diphthalonitrile (tetranitrile P) of formula

I, which can be used as a monomer in synthesis of polyhexazocylanes and polyphthalocyanines, as well as a semi-product in synthesis of polyether imides. The method involves, for example, reaction of 4-nitrophthalonitrile and resorcinol in the medium of an aprotic dipolar solvent in the presence of a base at 80-90°C in 1 hour. The starting compounds - 4-nitrophthalonitrile and resorcinol - are dissolved in N,N-dimethylacetamide and a solution of sesquihydrate potassium carbonate K₂CO₃·1.5H₂O in water is added to the obtained solution. The residue of the end tetranitrile P I separated from the reaction mass is then washed on a filter with an aliphatic alcohol selected from a group comprising methanol or ethanol or 2-propanol.

EFFECT: method enables to obtain tetranitrile P of higher purity with high output.

2 ex

Description

The invention relates to the chemistry of derivatives of dicarboxylic acids, and in particular to a method for producing and isolating 4,4 '- (m-phenylenedioxy) diphthalonitrile (tetranitrile P) of the formula I.

Tetranitrile P is used as a monomer for polyhexazocyclanes and polyphthalocyanines, as well as an intermediate in the synthesis of polyetherimides.

Known methods for the preparation, isolation and purification of tetranitrile P I by reaction of 4-nitrophthalonitrile II with resorcinol III in the presence of a deprotonating agent - K ₂ CO ₃ in N, N-dimethylformamide (DMF) medium [1-3] according to the scheme:

According to the method [1], the starting compounds II and III in DMF in the presence of K ₂ CO _{3 are} kept under stirring for 4.0-4.5 hours at 85-90 ° C and then the target product I is isolated by precipitation in water, separation of the precipitate, washing it with water and by drying. The disadvantages of this method include the low speed of the process and the insufficiently high purity of the target product.

The USSR author's certificate [2] describes a method for producing tetranitrile P I by reacting the starting compounds II and III in DMF containing 2-15 mol / mol II of water in the presence of K ₂ CO ₃ at 60-90 ° C for 0.5-3.5 h. After isolation of the target product by pouring the reaction mass into a 1% aqueous NaOH solution, separating the precipitate, washing with water and drying, the yield of compound I is 92-94%, the content of the basic substance is 99.4-99.7%. The disadvantages of this method include the insufficiently high purity of the target product.

The closest to the proposed technical solution is a method for producing tetranitro P I of RF patent [3], comprising reacting the starting compounds II and III in 75% aqueous DMF in the presence of K ₂ cos at a ratio II: III: K ₂ CO ₃ = 1.0: 0.0.5: 1.006, mol, in 75% aqueous DMF while stirring the reaction mass for 2 hours at 80 ° C. The target product I is isolated by cooling the reaction mass to 5 ° C, separating the precipitate and washing it on the filter with 75% aqueous DMF. Then, the resulting precipitate was transferred to a glass of water, suspended and stirred for 0.5 h, filtered off, washed on the filter with water until neutral and dried. Get tetranitrile P I with a yield of 89% - light beige powder with so pl. 183-184 ° C.

The disadvantage of this method is the insufficiently high purity of the target product and color, which negatively affects its use as an intermediate and monomer for polyetherimides and polyhexazacyclanes, respectively. According to high performance liquid chromatography (HPLC), tetranitrile P I, obtained and isolated by the described procedure, contains from 0.30 to 0.60% of monosubstitution product IV [4].

The objective of the present invention is a method for the production and isolation of tetranitrile P, which provides higher purity of the target product while maintaining a high yield.

The solution of this problem is achieved by the method of production and isolation of tetranitrile RI, the interaction of 4-nitrophthalonitrile and resorcinol in an aprotic dipolar solvent in the presence of a base at 80-90 ° C for 1 h, characterized in that the starting compounds are 4-nitrophthalonitrile and resorcinol dissolved in N, N-dimethylacetamide and the resulting solution is poured polutoravodnogo solution of potassium carbonate K ₂ CO ₃ · 1.5N ₂ O in water is then isolated from the reaction mixture of the title F I tetranitro precipitate was washed on the filter with aliphatic Peart, selected from the group consisting of methanol, or ethanol or 2-propanol.

Using DMAA can improve the purity of the target product and improve its color. The concentration of DMAA should be 75% (vol.). The ratio of reagents is II: III: K ₂ CO ₃ · 1.5H ₂ O = 1.01-1.02: 1.00: 1.10-1.20, mol. Moreover, the best results are obtained by adding a solution of potassium carbonate K ₂ CO ₃ · 1.5H ₂ O in water to a solution of the starting compounds in DMAA.

It is important when isolating the target product that the precipitate obtained after cooling the reaction mass is first washed on a filter with C1-C3 aliphatic alcohol, and then suspended in water and stirred at room temperature for 0.5 h.

The sequence of the above procedures in the proposed method provides 4.4 '- (m-phenylenedioxy) diphthalonitrile (tetranitrile P) with yields of 88-92% in the form of a white crystalline powder with a basic substance content (tetranitrile P) of 99.85-99.95% with an admixture of 0.15 -0.05% monosubstitution product IV according to HPLC.

The present invention is illustrated by the following examples.

Example 1. In a flask equipped with a stirrer, reflux condenser and thermometer and containing 1.2 L of N, N-dimethylacetamide (DMAA), 320.0 g (1.85 mol) of 4-nitrophthalonitrile and 101.7 g (0.92 mol) of resorcinol were loaded. A solution of 335.7 g (2.03 mol) of K ₂ CO ₃ -1.5H ₂ O in 350 ml of water was added to the resulting solution. The reaction mass was stirred at 80-85 ° C for 1 h, after which it was cooled to 5-10 ° C and the precipitate formed was filtered off. The precipitate was washed with ethanol (2 × 100 ml) and transferred to a beaker containing 1.0 L of water. The suspension was stirred at room temperature for 10 minutes, transferred to a filter and filtered. The filter cake was washed with water (3 × 100 ml) and dried at 70 ° C. Received 293.1 g (88% of theory) of 4.4 '- (m-phenylenedioxy) diphthalonitrile - a white crystalline powder with so pl. 184-185 ° C. Found,%: C 72.85; H 2.84; N, 15.37. C ₂₂ H ₁₀ N ₄ O ₂ . Calculated,%: C 72.93; H 2.78; N, 15.46. IR (KBr), cm ^-1 : 2231 (C≡N); 1247, 1123 (C-O-C-ether). 1 H-NMR, ppm: δ = 8.15 (d, ³ J = 8.8Hz, 2H, H ^6.6 ), δ = 7.93 (d, ⁴ J = 2.2Hz, 2H, H ^3.3 ), δ = 7.59 (t, ³ J = 8.4Hz, 1H, H ^{5 ''), δ = 7.56 (} dd, ³ J = 8.8Hz, ^{4 J = 2.2Hz, 2H, H 5,5} ), δ = 7.10-7,16 (m, 3H, H ^{2``4''6 ''} ). The content of the main substance (HPLC) is 99.90%.

Example 2. The filtrate obtained after separation of the precipitate from the reaction mass according to Example 1 was clarified by treatment with 100 g of activated carbon, filtered, DMAA was added to a volume of 1.2 L and used in the synthesis of tetranitrile R. The synthesis was carried out similarly to Example 1. The precipitate formed after cooling the reaction mass, washed with 2-propanol (2 × 100 ml) and the product was isolated as described above. Received 304.8 g (91.5% of theory) of 4.4 '- (m-phenylenedioxy) diphthalonitrile - a white crystalline powder with so pl. 183-184 ° C. The content of the main substance (HPLC) is 99.86%.

List of sources used

1. Synthesis of tetracarboxylic acid dianhydrides with ether linkages: Report (final). Yaroslavl Polytechnic Institute. Yaroslavl, No. G. R. 77068796, 1980, 98 pp.

2. Kaninsky P.S., Plakhtinsky V.V., Mironov G.S. et al. Method for producing 4,4 '- (arylenedioxy) diphthalonitriles. USSR copyright certificate No. 1509352, class С07С 120/00, 121/75. Claim 07/15/1987. Publ. 09/23/1989.

3. Kaninsky P.S. The method of obtaining mono - and diphthalonitriles. RF patent 2079488, cl. С07С 253/30, С07С 255/51. Claim 01/30/1995. Publ. 05/20/1997.

4. Lyubimtsev A., Vagin S., Syrbu S., Hanack M. European Journal of Organic Chemistry. - 2007. - N 12. - P. 2000-2005.

Claims (1)

The method of obtaining 4,4 '- (m-phenylenedioxy) diphthalonitrile (tetranitrile P) of the formula I

the interaction of 4-nitrophthalononitrile and resorcinol in an aprotic dipolar solvent in the presence of a base at 80-90 ° C for 1 h, characterized in that the starting compounds 4-nitrophthalonitrile and resorcinol are dissolved in N, N-dimethylacetamide and a solution is added to the resulting solution potassium carbonate K ₂ CO ₃ · 1.5H ₂ O in water, then the precipitate of the target tetranitrile P I isolated from the reaction mixture is washed on the filter with an aliphatic alcohol selected from the group consisting of methanol or ethanol or 2-propanol.