Heterocyclic analogs of pleiadiene. XV. Direct acylation of perimidines in the naphthalene ring. Synthesis of 4 (9)- and 6 (7)-acylperimidines

Lyakhovnenko

et al. 2007

Chem Heterocycl Compd

Self Cite

The use of 1,3,5-triazines 2 as formylating agents in the presence of a Lewis acid has been reported [1]. The use of substituted 1,3,5-triazines as acylating agent was not known. We have shown that formylation of perimidine 1 does not occur under these conditions. Formylation has been successfully carried out with a threefold excess of 1,3,5-triazine 2 in 80% PPA (4 g per mmol of perimidine) at 55-60°C for 1 h. The yield of perimidine-6(7) carbaldehyde (3a) was 91% under these conditions. The compound was separated by pouring the reaction mixture into water with subsequent basification of the solution with ammonia and extraction with ethyl acetate. Compound 3a was previously successfully obtained in a yield of less than 10% by the Vilsmeier reaction [2]. We have shown that by using substituted 1,3,5-triazine ketones 3b,c can be obtained. In this case the reaction time is 2.5 h at a temperature of 80 and 110°C respectively. + 1 2a-c PPA 3a-c 2, 3 a R = H, b R = Me, c R = Ph Perimidine-6(7)-carbaldehyde (3a). Yield 91%; mp 212-214°C ( from acetic acid) (mp 212-214°C [2]). A mixed melting point with a known sample gave no depression of the melting point. The 1 H NMR spectrum coincided with that cited in [2]. 6(7)-Acetylperimidine (3b). Yield 78%; mp 221-222°C (from aqueous ethanol) (mp 221-222°C [3]). A mixed melting point with a known sample gave no depression of the melting point.__________________________________________________________________________________________

Section: ____________________________________________________________mentioning

confidence: 99%

“…6(7)-Acetylperimidine (3b). Yield 78%; mp 221-222°C (from aqueous ethanol) (mp 221-222°C [3]). A mixed melting point with a known sample gave no depression of the melting point.…”

mentioning

confidence: 99%

Acylation of perimidine with 1,3,5-triazines in polyphosphoric acid

Аксенов

Lyakhovnenko

et al. 2007

Chem Heterocycl Compd

Self Cite

“…We were unable to separate the products in light of their similar chromatographic mobility. The formation of compound 3d may be attributed to the competing deacetylation of acylperimidine 1e [4] and subsequent reaction of perimidine 4 with triazine 2a. The proposed mechanism for the formation of 1,3,7-triazapyrenes 3 is given in the scheme below.…”

mentioning

confidence: 99%

Reaction of 6(7)-acyl-and 6(7)-formylperimidines with 1,3,5-triazines in poly-phosphoric acid

Аксенов

Писаренко

et al. 2008

Chem Heterocycl Comp

Self Cite

We have already shown that the 1,3,5-triazine-PPA* system is useful for the acylation and formylation of perimidines [2] and the synthesis of 1,2,3,7-tetraazapyrenes from 1H-naphtho [1,8-de][1,2,3]triazine (1,2,3-triazaphenalene) [3]. The present study is a continuation of our investigation of the synthetic scope of this system. The reaction of this system with 6(7)-acylperimidines 1a-c and 1e and 6(7)-formylperimidine (1d) was studied in present work.Since perimidines [2] and 1,2,3-triazaphenalene [3] undergo, in effect, double electrophilic attack by the system of 1,3,5-triazines 2 in PPA, we might have assumed that perimidines 1 would react analogously. Indeed, 1,3,7-triazapyrenes 3a-d were obtained in 50-65% yield upon heating 1a-d with 1,3,5-triazine (2a) in PPA. N N R N R 1 N H R N O R 1 N N N 1a-e 3a-e + 2a PPA 1, 3 a R = H, R 1 = Ph, b R = Me, R 1 = Ph, c R = R 1 = Ph, d R = R 1 = H, e R = H, R 1 = Me _______ * PPA with 86% P 2 O 5 prepared according to Uhlig [1] was used. __________________________________________________________________________________________

“…Since 4(9)-isomeric aldehydes, ketones, and sulfones are formed together with 6(7) derivatives on acylation, formylation, and arene sulfonation [5][6][7], it seemed of interest to investigate the possibility of their prototropic conversions, and also the degenerate tautomerism of 4,9-disubstituted analogs. Due to the formation of an extremely stable intramolecular hydrogen bond between the NH proton and the oxygen of the carbonyl group, the 4(9)-formyl-(4, 6) and 4(9)-acetylperimidines (5, 7) in nonpolar solvents, and judging overall, in the solid state exist exclusively in the chelated 9-CO form.…”

mentioning

confidence: 99%

Heterocyclic analogs of pleiadiene 76. Synthesis and tautomeric conversions of mono- and disubstituted perimidines with electron-withdrawing substituents in the naphthalene fragment

Пожарский

Filatova

et al. 2010

Chem Heterocycl Comp

Self Cite

A series of new mono-and disubstituted perimidines with electron-withdrawing substituents in the naphthalene fragment has been synthesized. Their prototropic annular tautomerism has been investigated by 1 H NMR spectroscopy.We reported previously on the extremely slow annular prototropic tautomerism of derivatives of 2-trifluoromethylperimidine containing a formyl, acetyl, or p-toluenesulfonyl group in position 6(7) [2,3]. This phenomenon is expressed in the 1 H and 19 F NMR spectra of these compounds by the simultaneous observation of signals of both tautomers in low polarity solvents at room temperature and even on heating to 120-130 o C. It is assumed that the reason for this is the low basicity of these compounds in combination with spatial screening of both heteroatoms not only from the side of the 2-CF 3 substituent but also from the hydrogen atoms in positions 4 and 9.In the light of this it seemed of interest to investigate the prototropic tautomerism of 2-tertbutylperimidine (1) and also of the product of its 6(7)-acylation. It was expected that, not being an acceptor but being large, the tert-butyl group may hinder transfer of proton.We obtained compound 1 by the action of pivaloyl chloride on 1,8-naphthalenediamine. On acylation with acetic acid in PPA at 70-75 o C the isomeric 6(7)-and 4(9)-diacetyl derivatives of 2-tert-butylperimidine 2 and 3 were synthesized in 66 and 11% yield respectively.The 1 H NMR spectrum of 2-tert-butylperimidine (1) in CDCl 3 was unresolved. A strongly broadened peak of the ortho protons (H-4 and H-9) and a multiplet signal of the remaining aromatic protons indicated a somewhat slow prototropy. However, unlike other perimidines, the picture of the spectrum is practically