SU798095A1 - Method of preparing 4(2)-dimethylaminonaphthalene-1,8-dicarboxylic acid anhydride - Google Patents

Description

This invention relates to a process for the preparation of a naphthalene variety of anhydride 4 (2) -dimethyl-aminonaphthalene-1,8-dicarboxylic acid of formula tfiW which can be used as an intermediate for dyes and fluorescent substances. A known method for producing 4-aminonaphthalene-1,8-dicarboxylic anhydride by nitrating acenaphthene, oxidizing 4-nitroacetonefen to 4-nitronaphthalene-1,8-dicarboxylic acid anhydride and reducing the latter. and acetic acid and sodium bisulfate. The yield of the target product is 80-85%, counting on 4-nitronaphthalic anhydride or 30-40% on acenaphene IJ and 2. However, the preparation of pure 4-nitronaphthalic anhydride in the technique is fraught with great difficulties due to the formation of side 3-nitroacene-naphthene during nitration. There is also known a method for producing imides of 4-dialkylaminonaphthalene-1,8-dicarboxylic acid by replacing the substituent in the naphthalene part of the molecule with the dialkylamino group by the action of the secondary amine t3l. In this way, it is impossible to obtain an individual compound of the general formula T, since the impurity of the primary amine in the secondary, used in the reaction with a considerable excess, leads to the known reaction of acylation of amines with the formation of imides. The use of a secondary amine, purified from the primary impurity, greatly increases the cost of the secondary and, thus, the cost of synthesis increases. In addition, the use of solutions of secondary amines requires the reaction in an autoclave with a significant excess of amine. The purpose of the invention is to create an accessible method for preparing a compound of formula T and expanding the range of intermediates for dyes and fluorescent substances.

The goal is achieved by the fact that the compound of the formula

00

where .X is halogen or Ni; DOGpyppa., is subjected to interaction with c / 3- (H N-dimethylamino) -propionitrile in an organic solvent at 100200 s, preferably 115-170 ° C, at normal pressure.

The use of tertiary amines, one alkyl group of which contains a substituent in the |% position to the nitrogen (CN-group), facilitates the reaction, which is associated with low stability of () -substituted derivatives of carboxylic acids.

Excess tertiary amine or hydrocarbons, for example o-xylene, aliphatic alcohols, (for example, isoamyl), aliphatic acids (for example, acetic acid) are used as organic solvent.

Example. In a three-necked flask with a stirrer, a thermometer and a reflux condenser, 2.77 g (0.01 g mol) of 4-bromonaphthalene-1 anhydride, 8-dicarboxylic acid anhydride are placed, and 2.94 g (0.03 g / mol, 3 , 4 ml, d 0.865 g / cmO f3- (N N-dimethylamino) propionitrile. The solution is boiled for 3 hours until the starting material is absent according to the chromatogram on silufol in chloroform, dried onto water, the fallen precipitate is filtered, washed with water and dried .

Obtain 2.20 g of the yellow substance of anhydride 4-dimethylamino-naphthalen-1, 8-dicarboxylic acid .. Output 5 91.3% (from theory).

205-207®С, and after the crystal pl. isoamyl alcohol T

square

209.5-210 ° C. Gross formula: С Н N О

Elemental analysis:: -f4 -f-g 0 Found,% 69.25-69.52; H 4,714, 75; N 6.05-5.96.

Calculated%: C 69.70; H 4.60; N 5.81.

The maximum absorption is 410 nm (in benzene). The maximum fluorescence is 473 nm (in benzene).

NMR spectra were measured at NRS.

Example 2. In a three-necked flask with a stirrer, a thermometer and a reflux condenser, 2.77 g (0.01 g / mol) of 4-bromonaphthalene-1 anhydride, 8-dicarboxylic acid anhydride are placed, added with 70 ml of isoamyl alcohol and heated to boiling; g (0.04 g / mol (d = 0.865 g / cm; 4.53 ml) of JJ- (N, N-dimethylamino) -propionitrile) is added to the solution. The solution is boiled for 5 h (control-absence of the starting material in the chromatogram in Silufol in chloroform® 50 ml of isoamyl alcohol are distilled off. The mixture is cooled and the yellow precipitate formed is filtered off and dried. Dryden dimetilaminrnaftalin 4-1,8-dicarboxylic acid, yield 75% (of theory). chromatographically and IR spectrum identical to material obtained in Example 1.

P r and measures 3. In a three-necked flask with a stirrer, a thermometer and a reflux condenser, 0.46 g (0.002 g / mol) of 4-chloronaphthalic is placed

anhydride, give 14 ml of ortho-xylene and 0.45 ml (0.004 g / mol) p) - (N Ndimethylamino) -propionitrile. The solution is boiled for 8 h (control-absence of the initial chromatogram on a forcefol in chloroform). The product is isolated by distilling off the solvent in a water jet pump vacuum. 0.39 g of 4-dimethylaminonaphthalene-1,8-dicarboxylic anhydride is obtained, yield 81.3% (from theory). Chromatographically and by IR spectrum of the substance is identical to that obtained in example 1.

Example 4. A 0.24 g (0.001 g / mol) of 4-nitronaphthalic anhydride is added to a three-necked flask with a stirrer, a thermometer, and a water condenser. 2.94 g (0.03 g / mol) 3.4 ml ,, d 0.865 g / cm) L- (M, N-dimeo tylamino) -propionitrile. The solution is boiled for 3 h (control-absence of the original substance according to the chromatogram on silofole in chloroform). The resulting solution is drunk on water

5 and the precipitated precipitate is filtered off.

washed with water and dried. O, 23 g of 4-dimethyl-aminonaphthalene-1,8-dicarboxylic anhydride is obtained, yield 96% (from theory). Chromatographically and by IR spectrum, the substance is identical to that obtained by the example. one,

Example5. 2.77 g (0.01 g / mol) of 2-iodonaphthalic anhydride are placed in a three-neck flask with a stirrer, thermometer and reflux condenser, 2.94 g (0.03 g / mol 3.4 ml, d 0.865 g / cm)) -. (N, N-dimethylamino) -propionitrile. The solution is boiled for 3 hours until the starting material is absent from the cbL matrix on silufol in chloroform. The resulting solution is drunk on water and the precipitate is filtered off, washed with water and dried, and 2.00 is obtained. g of yellow hydrate of 2-dimethylamino-naphthalen-1, 8-d.carboxylic acid anhydride. Output 83.0% (from theory). T, 154-155 s, Vrutto-formula С..Н N0,. . Elemental analysis:

4.72ff 5 "™ ° °": from 69.70 j to 4.60 j

Claims (2)

Claim 1. The method of obtaining the anhydride of '4 (2) -dimethylaminonaphthalene-1,8-dicarboxylic acid of the formula. Characterized in that the compound of formula (k) where X is a halogen or nitro group, is subjected to interaction with β- (Ν, Ν-dimethylamino) -propionitrile in an organic solvent at a temperature of 100-200 ° C. 2. The method of pop. 1, characterized in that an excess of tertiary amine or is used as an organic solvent. . hydrocarbons.