Derivatives of Diphenic Acid
Abstract Generated abstract
This paper describes the synthesis of mixed-function derivatives of 2,2′-diphenic acid, specifically ethyl and phenyl esters of substituted monoamides, motivated by prior indications of herbicidal activity among related diphenic acid amides and the known selectivity of aromatic carboxylic esters. The compounds were prepared from corresponding monoamides by esterification with ethanol in sulfuric acid or with phenol in the presence of phosphorus oxychloride, followed by purification and recrystallization. Sixteen crystalline ester-amides bearing nitro, chloro, methyl, anilide, and naphthylamide substituents are reported with melting points and elemental analyses. The study finds that chloro- and nitro-substituted amides react more readily with ethanol and phenol than unsubstituted anilide and toluidide analogues, while herbicidal testing is deferred to later work.
Full Text
DERIVATIVES OF DIPHENIC ACID
II. Esters of Substituted Monoamides of 2,2′-Diphenic Acid
L. P. Kulev, G. M. Stepanova
As was reported earlier [1], some of the substituted amides of diphenic acid obtained by us deserve attention as substances with high herbicidal activity.
It is also known that esters of aromatic carboxylic acids, as a rule [2], possess a considerably stronger and more sharply expressed selective herbicidal action than the acids themselves.
Derivatives of diphenic acid have, in this respect, generally not been studied.
It was of interest to synthesize compounds with mixed functions, i.e., esters of monoamides of 2,2′-diphenic acid of the general formula
\[ \begin{array}{c} \text{diphenic acid skeleton bearing } \mathrm{CONH{-}Arx} \text{ and } \mathrm{COOR} \text{ groups} \end{array} \]
\[ x=\mathrm{NO_2,\ Cl,\ CH_3} \]
\[ R=\mathrm{C_2H_5,\ C_6H_5} \]
The indicated derivatives of diphenic acid were obtained from the corresponding amides by heating them with ethyl alcohol in the presence of sulfuric acid, or with phenol in the presence of phosphorus oxychloride (by analogy with the known synthesis of salol).
The reaction products are resin-like substances which pass into the crystalline state after careful treatment with a solution of soda and repeated recrystallization from alcohol.
Chloro- and nitro-substituted amides of diphenic acid react with ethyl alcohol and phenol considerably more readily than amides that do not contain electronegative substituents.
All the amide esters described here are crystalline substances, soluble in alcohol, acetone, ether, benzene, and chlorobenzene.
Data on the herbicidal activity of the compounds obtained will be reported later.
Experimental Part
Ethyl ester of diphenic acid monoanilide (I). Obtained from 15.8 g of diphenic acid monoanilide [3], 80 ml
ethyl alcohol and 20 ml of concentrated sulfuric acid are heated in a flask equipped with a reflux condenser and stirrer on a water bath for 3 hours. The reaction mixture, without cooling, is poured into cold water. The resinous product is washed with water, then with a solution of soda, and recrystallized from alcohol. Colorless crystals, m.p. 96°. Found, %: N 4.20. \(\mathrm{C}_{22}\mathrm{H}_{19}\mathrm{O}_{3}\mathrm{N}\). Calculated, %: N 4.05.
Ethyl ester of mono-2-nitroanilide of diphenic acid (II). Prepared analogously to (I) from 18.1 g of mono-2-nitroanilide of diphenic acid, 80 ml of ethyl alcohol, and 20 ml of concentrated sulfuric acid. Large light-yellow lustrous crystals, m.p. 100°. Found, %: N 7.18. \(\mathrm{C}_{22}\mathrm{H}_{18}\mathrm{O}_{5}\mathrm{N}_{2}\). Calculated, %: N 7.17.
Ethyl ester of mono-3-nitroanilide of diphenic acid (III). Prepared analogously to (I) from 18.1 g of mono-3-nitroanilide of diphenic acid, 80 ml of ethyl alcohol, and 20 ml of concentrated sulfuric acid. Fine, almost colorless crystals, m.p. 90–91°. Found, %: N 7.2. \(\mathrm{C}_{22}\mathrm{H}_{18}\mathrm{O}_{5}\mathrm{N}_{2}\). Calculated, %: N 7.17.
Ethyl ester of mono-4-nitroanilide of diphenic acid (IV). Prepared analogously to (I) from 18.1 g of mono-4-nitroanilide of diphenic acid, 80 ml of ethyl alcohol, and 20 ml of concentrated sulfuric acid. Almost colorless needles, m.p. 109–110°. Found, %: N 7.36. \(\mathrm{C}_{22}\mathrm{H}_{18}\mathrm{O}_{5}\mathrm{N}_{2}\). Calculated, %: N 7.17.
Ethyl ester of mono-4-chloroanilide of diphenic acid (V). Prepared analogously to (I) from 17.57 g of mono-4-chloroanilide of diphenic acid, 80 ml of ethyl alcohol, and 20 ml of concentrated sulfuric acid. Colorless lustrous crystals, m.p. 65–66°. Found, %: N 3.79; Cl 9.50. \(\mathrm{C}_{22}\mathrm{H}_{18}\mathrm{O}_{3}\mathrm{NCl}\). Calculated, %: N 3.69; Cl 9.35.
Ethyl ester of mono-2-toluidide of diphenic acid (VI). Prepared analogously to (I) from 16.55 g of mono-2-toluidide of diphenic acid, 80 ml of ethyl alcohol, and 20 ml of concentrated sulfuric acid. Colorless crystals, m.p. 70–72°. Found, %: N 3.90. \(\mathrm{C}_{23}\mathrm{H}_{21}\mathrm{O}_{3}\mathrm{N}\). Calculated, %: N 3.90.
Ethyl ester of mono-4-toluidide of diphenic acid (VII). Prepared analogously to (I) from 16.55 g of mono-4-toluidide of diphenic acid, 80 ml of ethyl alcohol, and 20 ml of concentrated sulfuric acid. Colorless crystals, m.p. 70–72°. Found, %: N 4.09. \(\mathrm{C}_{23}\mathrm{H}_{21}\mathrm{O}_{3}\mathrm{N}\). Calculated, %: N 3.90.
Ethyl ester of mono-1-naphthylamide of diphenic acid (VIII). Prepared analogously to (I) from 18.35 g of mono-1-naphthylamide of diphenic acid, 80 ml of ethyl alcohol, and 20 ml of concentrated sulfuric acid. Colorless needles, m.p. 92°. Found, %: N 3.56. \(\mathrm{C}_{26}\mathrm{H}_{21}\mathrm{O}_{3}\mathrm{N}\). Calculated, %: N 3.54.
Phenyl ester of mono-2-nitroanilide of diphenic acid (IX). 18 g of mono-2-nitroanilide of diphenic acid and 4.64 g of phenol are heated in a flask equipped with a reflux condenser and stirrer to 60°, and 2.1 g of phosphorus oxychloride is added dropwise; the temperature is raised to 140–145° and the mixture is heated with stirring for 4 hours. The contents of the flask are poured into water; the resinous product formed is thoroughly washed with a 10% solution of soda and recrystallized from alcohol. White finely crystalline powder, m.p. 110°. Found, %: N 6.24. \(\mathrm{C}_{26}\mathrm{H}_{18}\mathrm{O}_{5}\mathrm{N}_{2}\). Calculated, %: N 6.40.
Phenyl ester of mono-3-nitroanilide of diphenic acid (X). Prepared analogously to (IX) from 18.1 g of mono-3-nitroanilide of diphenic acid, 4.7 g of phenol, and 2.1 g of phosphorus oxychloride. Colorless crystals, m.p. 150–151°. Found, %: N 6.19. \(\mathrm{C}_{26}\mathrm{H}_{18}\mathrm{O}_{5}\mathrm{N}_{2}\). Calculated, %: N 6.40.
Phenyl ester of diphenic acid mono-4-nitroanilide (XI). Obtained analogously to (IX) from 18.1 g of diphenic acid mono-4-nitroanilide, 4.7 g of phenol, and 2.1 g of phosphorus oxychloride. Light-yellow crystals with m.p. 121–122°. Found, %: N 6.37. \( \mathrm{C}_{26}\mathrm{H}_{18}\mathrm{O}_{5}\mathrm{N}_{2} \). Calculated, %: N 6.40.
Phenyl ester of diphenic acid monoanilide (XII). Obtained analogously to (IX) from 15.85 g of diphenic acid monoanilide, 4.7 g of phenol, and 2.1 g of phosphorus oxychloride. Colorless crystals with m.p. 124–125°. Found, %: N 3.54. \( \mathrm{C}_{26}\mathrm{H}_{19}\mathrm{O}_{3}\mathrm{N} \). Calculated, %: N 3.56.
Phenyl ester of diphenic acid mono-2-toluidide (XIII). Obtained analogously to (IX) from 16.55 g of diphenic acid mono-toluidide, 4.7 g of phenol, and 2.1 g of phosphorus oxychloride. Colorless crystals with m.p. 126°. Found, %: N 3.65. \( \mathrm{C}_{27}\mathrm{H}_{21}\mathrm{O}_{3}\mathrm{N} \). Calculated, %: N 3.44.
Phenyl ester of diphenic acid mono-4-toluidide (XIV). Obtained analogously to (IX) from 16.55 g of diphenic acid mono-4-toluidide, 4.7 g of phenol, and 2.1 g of phosphorus oxychloride. Colorless crystals with m.p. 120°. Found, %: N 3.35. \( \mathrm{C}_{27}\mathrm{H}_{21}\mathrm{O}_{3}\mathrm{N} \). Calculated, %: N 3.44.
Phenyl ester of diphenic acid mono-4-chloroanilide (XV). Obtained analogously to (IX) from 17.51 g of diphenic acid mono-4-chloroanilide, 4.7 g of phenol, and 2.1 g of phosphorus oxychloride. Colorless crystals with m.p. 119–120°. Found, %: N 3.25. \( \mathrm{C}_{26}\mathrm{H}_{18}\mathrm{O}_{3}\mathrm{NCl} \). Calculated, %: N 3.27.
Phenyl ester of diphenic acid mono-1-naphthylamide (XVI). Obtained analogously to (IX) from 18.35 g of diphenic acid mono-1-naphthylamide, 4.7 g of phenol, and 2.1 g of phosphorus oxychloride. Shiny colorless crystals with m.p. 155–156°. Found, %: N 3.36. \( \mathrm{C}_{30}\mathrm{H}_{21}\mathrm{O}_{3}\mathrm{N} \). Calculated, %: N 3.16.
Conclusions
-
Ethyl and phenyl esters of monoamides of diphenic acid have been synthesized.
-
It has been established that amides with electronegative substituents (chlorine, nitro group) react with ethyl alcohol and phenol considerably more readily than anilide and toluidides.
LITERATURE
-
L. P. Kulyov, G. M. Stepanova. Izvestiya TPI, vol. 111, 16, 1961.
-
Yu. A. Baskakov. Itogi nauki. Biologicheskie nauki. 2. Chemical means of stimulating and inhibiting physiological processes in plants. Publishing House of the Academy of Sciences of the USSR, 224, 1958.
-
W. H. Warran und R. A. Briggs. Über die Einwirkung von Thionylchlorid auf einige Anilsäuren. Ber. Dtsch. chem. Ges. 64, 26–30, 1931.