CS198794B1 - Substituted 4,4'-dinitro-n,n'-bisphenyl -dicarboxybenzene diamides and method for preparing them - Google Patents

Description

The invention relates to substituted 4,4-dinitro-N, N-bisphenyldicarboxybenzenediamides and a process for their preparation by nitration of the respective substituted N, N'-bisphenyldicarboxybenzenediamides.

The present invention provides substituted 4,4'-dinitro N, N'-bisphenyldicarboxybenzene diamides of formula I:

^R1 > -A z * ¹

NO ₂ - <Q-HN-OC- -CO-NH-O-M02 * ² (I), wherein R ₁ and R ₂ are hydrogen, methyl, chloro, methoxy, or ethoxy, wherein R 1 and R ₂ may be identical or different, but only one symbol may be hydrogen and a process for their preparation by treating the diamides of the formula IX

Ri

HN-OC

CO-NH

(XI) R ₂

198 794

198 794 where Ηχ and Rg are as defined above with nitrating agents in strongly polar compounds with a dielectric constant greater than 6.

The diamides of formula II can be obtained, for example, by reaction of benzenedicarboxylic acid dichlorides and amines of formula III

R2 (III) wherein R @ 1 and R @ 8 are as defined above or by reaction of benzenedicarboxylic acid esters and amines of formula III according to the method of author's certificate No. 193444.

From nitrating agents, practically all known types used in nitration of aromatic compounds such as 65 to 67% nitric acid, fuming nitric acid, nitric acid-sulfuric acid mixtures can be applied in a wide range of concentrations of both components and their proportions and inorganic nitrates added to strongly acidic medium in which the diamides of formula II are present. Owing to the relatively low solubility of the diamides of the formula II in conventional organic solvents, it is advisable to mix them with polar compounds, possibly strongly acidic, which, by their ability to dissolve and absorb the reaction heat, facilitate the dinitration process. Compounds having a dielectric constant greater than 6 which are inert to nitrating agents are suitable. By way of illustration, sulfuric acid, phosphoric acid, acetic acid, acetic anhydride, dimethylsulfoxide, aliphatic amides such as formamide, monoethyl and dimethylformamide, acetamide, nitriles and the like can be mentioned.

In the novel process, an alternative is preferred where the selected diamide of formula II is dissolved in sulfuric acid, then nitrated either with 65-70% nitric acid alone, or with concentrated (fuming) or a mixture of nitric acid and sulfuric acid, or nitrates from which nitric acid is released in a strongly acidic environment.

The ratio between the nitrating agent and the diamide is selected such that there is at least two equivalents of reagent per 1 mol of diamide. A slight excess of nitrating agents is not a problem and, on the contrary, facilitates the entry of two nitro groups into the diamide molecule of formula II; up to 20% excess can be used without undesirable polynitration or side oxidation reactions.

When dissolving diamides in strongly acidic environments, it is advisable to work at temperatures below 100 ° C, otherwise there is a risk of hydrolysis of amidic bonds and, in the case of work with concentrated sulfuric acid, a risk of sulfonation.

Due to the ease of dinitration, there is no need to resort to high reaction temperatures (risk of hydrolysis). For compounds that are stable in strongly acidic environments even at elevated temperatures, dissolution and dinitration can be conducted at temperatures above 100 ° C.

In cases where the solubility of the final dinitroderivatives is higher than the component ejection, it is desirable to select a number of polar impurities when mixed with the diamides II to form a suspension which will only dissolve during nitration. This measure leads to an alternative

198 794 nitration in sulfuric acid, to reduce the proportion of sulfuric acid in the waste water, thereby rationalizing their disposal.

Example 1

0.05 mol of N, N'-bis (3-methylphenyl) -terephthaldiamide, i.e. 17.57 g of 98®, is mixed with 100 ml of 09% sulfuric acid at 15-20 ° C and after stirring under vigorous stirring and external cooling is nitrated by dropwise addition of 6.0 ml of 65% nitric acid at 25-30 ° C. After the addition of nitric acid, the reaction mixture was stirred for 1/2 hour at 30 ° C and then diluted by pouring onto 100 g of ice. The resulting suspension is diluted with an additional 200-400 ml of water, stirred, filtered and washed to remove acidity. The crude dinitro product is dried at 50 ° C to constant weight.

19.8 g of N, N * -bis (4-nitro-3-methylphenyl) terephthaldiamide are obtained in the form of a ocher powder, corresponding to 91.2% of th.

Elemental analysis found the following composition:

. 60.62% C, 4.27% H, 12.93% N, and this elemental content is in good agreement with the composition that corresponds to the ^C 22 ^H 18 ° 6 ^Ii 4 ^dinitrosyls (mh 434.20) formulas Content: 60.82% C, 4.18% H, 22.10% 0, 12.90% N.

Example 2

0.05 mol of N, N'-bis (2'-methylphenyl) terephthaldiamide, i.e. 17.40 g of 99%, is filtered analogously to Example 1.

19.1 g of N, N'-bis (4 ^of -nitro-2-methyl-phenyl) -terephthaldiamide are obtained in the form of a tan powder.

Elemental analysis revealed the composition:

60.91% C, 4.24% H, 12.70% N, which is in agreement with the theoretical composition dinitroeloučeniny mentioned empirical formula ^C 2 ^H 18 ^N ° 6 4 ^{86 8 t} ^ ^{n m} ®ď percentage of an element as described in Example 1.

Example 3

0.05 mol of N, N'-bia (2,5 '-dimethylphenyl) terephthaldiamide, i.e. 18.62 g of 100% of the substance, is internalized in a manner similar to that described in Example 1.

22.2 g of N, N -bis (4-nitro-2 ^from 5- dimethylphenyl) -terephthaldiamide as a tan powder, i.e. 96% of theory.

Elemental analysis revealed the composition:

% C, 62.01;% H, 5.05;% N, 12.33. This is consistent with the theoretical composition of the dinitro compound of the summary formula # 24 ^ 22 ^ 6 ^ 4 (MW 462.46) containing 62.30% C, % H, 20.76;% N, 12.12.

Example 4

0.05 ml of N (N '-bis (2-ethoxy-phenyl) -isophthalic diamide), ie 21.2 g of 96% of the substance

198 794 as in Example 1. 23.1 g of N, N-bis (4-nitro-2-ethoxyphenyl) isophthaldiamide are obtained in the form of a yellowish-brown precipitate, corresponding to a yield of 93.5% of th.

Elemental analysis revealed the composition:

57.95% C, 4.70% H, 11.81% N, which agrees with the theoretical composition for the dinitro compounds of the summary formula ^C 24 ^H 22 ° 8.1 ^, 4 (MW 494.45) and content: 58.30% C H 4.48, N 25.89, N 11.33 (MW 494.45)

Example 5

0.05 moles of N, N'-bi8 (2-methoxy-5-methyl) terephthaldiamide, i. 20.22 g of 100% of the substance were internalized as in Example 1. 24.25 g of N, N'-bis (4'-nitro-2-methoxy-5'-methylphenyl) terephthaldiamide was obtained as an ocher powder, i.e. 98%. % th.

Elemental analysis revealed the composition:

% C, 58.10;% H, 5.04;% N, 10.98, which is consistent with the theory of the dinitro compound of the formula (24 ^ 22 ^ 8 ^ 4 ^ ^m · ^ · 494.46). H, 4.48; N, 25.89; N, 11.33

Example 6

0.05 mol of N, N'-bis (2,5 '-dichlorophenyl) terephthaldiamide m.p. 22.7 g of 100% of the substance were internalized in the same manner as in Example 1. 26.56 of an ocher-colored dinitro compound was obtained, i.e. 97.5% of th.

Elemental analysis revealed the composition:

44.37 C, 2.13% H, 10.02% N, 26.50% Cl, which is consistent with the theoretical composition of the dinitro compound of the general formula C 8 H 8 QOgN 4 Cl 2 (mh 544.15) containing 44.14 % C, 1.85% H, 17.64% N, 10.30% N, 26.06% Cl.

Example 7

0.05 mole of N, N'-bis (3-methylphenyl) -terephthaldiamide and e is dissolved in sulfuric acid as in Example 1, then a total of 8.81 g of ammonium nitrate is added in portions at 25-30 ° C instead of sulfuric acid. The procedure is the same as in Example 1. 19.3 g of the corresponding dinitro compound are obtained.

The melting points of all compounds are above 300 ° C.

Claims (3)

Substituted 4,4'-dinitro-Ν, Ν'-bisphenyldicarboxybenzene diamides of the general formula I * 2 R ₂ wherein R 1. and R g are hydrogen, methyl, chloro, methoxy or ethoxy, wherein R 6 and R 8 may be the same or different, but only one symbol may be hydrogen. A process for the preparation of substituted 4,4'-dinitro-Ν, Ν'-bisphenyldicarboxybenzenediamides of the formula I, characterized in that the diamides of the formula II are R ₂ R ₂ where R 1 and R 8 are as defined above, act with nitrating agents in strongly polar compounds with a dielectric constant of greater than 6. 3. A process according to claim 2, characterized in that it is carried out in the presence of sulfuric acid.