Synthesis of Some Phenanthridone Derivatives
Abstract Generated abstract
This paper describes the preparation of previously unreported substituted phenanthridone derivatives, motivated by interest in phenanthridine and phenanthridone systems as components of alkaloids and medicinal compounds. Starting from fluorenone-4-carboxylic acid and its butyl ester, the authors applied established rearrangement and functionalization methods in polyphosphoric acid to obtain phenanthridone-9(10H)-4-carboxylic acid, its butyl ester, 4-aminophenanthridone-9(10H), and acetyl and benzoyl derivatives of the amine. Product identities were supported by melting points, functional group tests, UV spectra, and elemental or quantitative analyses, with reported yields ranging approximately from 25% to 60%.
Full Text
Synthesis of Some Phenanthridone Derivatives
A. P. Belyaeva, A. N. Novikov
(Presented by the scientific seminar of the departments and laboratories of organic synthesis, KhTF)
Phenanthridine systems, the nitrogen analog of phenanthrene, and phenanthridone are components of certain alkaloids and medicinal preparations [1]. Because of gaps in information on the influence of the structure of compounds of this series on physiological activity, it was of interest to obtain representatives of this series and to study their action on the organism. The present work reports the results of studies on the synthesis, from fluorenone-4-carboxylic acid, of certain substituted phenanthridones not described in the literature. The chemical transformation methods used, well studied and described for other objects, leave no doubt as to the structure of the newly obtained compounds. To confirm their structures, UV spectra and the results of quantitative functional and elemental analyses were also used.
Fig. 1. UV spectra: 1—4-aminophenanthridone-9(10H); 2—butyl ester of phenanthridone-9(10H)-carboxylic-4-acid; 3—phenanthridone-9(10H)-carboxylic-4-acid; 4—methyl ester of phenanthridone-9(10H)-carboxylic-4-acid; 5—phenanthridone 9(10H)
Phenanthridone
Experimental Part
Synthesis of phenanthridone-9(10H)-carboxylic-4-acid [2]. To polyphosphoric acid, obtained from 150 g of phosphorus anhydride and 100 ml of 85% phosphoric acid at a temperature of 50°C, ...
...was added, with mechanical stirring, to 15 g of fluorenonecarboxylic acid and, in portions over the course of three hours, 4.3 g of sodium azide. The mixture was heated for six hours at 90°C. Upon completion of the reaction, the thick viscous mass was poured into a beaker containing 500 ml of cold water. The precipitate that separated was filtered off and reprecipitated from a 20% aqueous solution of sodium carbonate with hydrochloric acid. The phenanthridonecarboxylic acid was then purified by crystallization from isopropyl alcohol. Yield 55–60%, m.p. 320°C. Found, %: C 70.31; H 4.24; N 5.74; molecular weight 229; carboxyl groups 17.3. C₁₄H₉NO₃. Calculated, %: C 70.29; H 3.76; N 5.85; molecular weight 239; carboxyl groups 18.5.
Similarly, from 15 g of the butyl ester of fluorenonecarboxylic acid and 3.5 g of sodium azide in the presence of polyphosphoric acid (150 g of phosphorus pentoxide and 120 ml of phosphoric acid), the butyl ester of phenanthridone-9(10)-carboxylic-4-acid was obtained in 35–40% yield, with m.p. 180°C. The reaction for the carboxyl group was negative. Found, %: N 4.90; C₁₈H₁₇NO₃. Calculated, %: N 4.75.
Preparation of 4-aminophenanthridone-9(10 H) by the method of Lossen, modified by Snyder [3]. To polyphosphoric acid prepared from 150 g of phosphorus pentoxide and 100 ml of orthophosphoric acid, with mechanical stirring, were added 15 g of phenanthridone-9(10 H)-carboxylic-4-acid and 4.5 g of hydroxylamine hydrochloride. The mixture was heated in an oil bath at 160° for 6 hours, then poured into a sodium hydroxide solution. The precipitate of 4-aminophenanthridone-9(10 H) was filtered off and recrystallized from ethyl alcohol. Yield 30–35%, m.p. 285°C with decomposition. The qualitative reaction for the amino group was positive, and for the carboxyl group negative.
Acylation of 4-aminophenanthridone-9(10 H). A mixture of 12 g of aminophenanthridone and 50 ml of dry benzene was heated in an oil bath, and at 140°C 4.3 ml of acetyl chloride was gradually added dropwise with mechanical stirring. The synthesis time was 5 hours. The reaction mass was cooled, the precipitate was filtered off and recrystallized from aqueous dimethylformamide. Yield of 4-acetylaminophenanthridone-9(10 H) 25–30%, m.p. 324°C with decomposition. Found, %: C 72.00; H 4.77; N 11.19; C₁₅H₁₂N₂O₂. Calculated, %: C 71.83; H 4.76; N 11.11.
Similarly, 4-benzoylaminophenanthridone-9(10 H) was obtained. Yield 30–35%, m.p. 335°C with decomposition. Found, %: C 76.80; H 4.61; N 8.57. C₂₀H₁₄N₂O₂. Calculated, %: C 76.43; H 4.46; N 8.91.
Conclusions
By known methods, phenanthridone-9(10 H)-carboxylic-4-acid, its butyl ester, 4-aminophenanthridone-9(10 H), and its acetyl and benzoyl derivatives, not described in the literature, have been synthesized.
References
- Heterocyclic Compounds, vol. IV, pp. 431, 472, Foreign Literature Publishing House, Moscow, 1955.
- R. T. Conley, J. Organic Chemistry, 23, 1330 (1958).
- A. Serrey, Handbook of Organic Reactions, p. 175, State Chemical Publishing House, Moscow, 1962.