V. I. Goncharov

A new one pot reaction of perimidines with nitroethane and sodium nitrite in polyphosphoric acid

Development of new efficient synthetic methods for poorly available compounds possessing useful properties is an actual problem. Polynuclear aromatic and hetero aromatic compounds with peri annulated five membered rings belong to such compounds. If there are known plenty of methods for the peri annulation of pyrrole1—4 and furan4 ring to naphthalene derivatives, only several examples are described for the peri annulation of pyrazole ring.4—6 In the present work, we suggest a method for the syn thesis of compounds containing such a fragment, which is based on the reaction of electrophilic acetamidation of arenes with nitroethane in PPA recently discovered in our laboratory.7—9 We showed that the reaction of perimidines 1a—c and nitroethane in the molar ratio of 1 : 2 (Scheme 1) in the presence of catalytic amounts of DABCO in polyphos phoric acid (PPA) at 100—105 C for 3 h with subsequent addition of NaNO2 in the amount equimolar to that of nitroethane and heating for another 6 h at this tempera ture leads to 1,2,5,7 tetraazacyclopenta[c,d]phenalenes 5a—c in 26—33% yields. Earlier, such compounds were obtained in close yields using the following synthetic se quence: the Schmidt reaction—nitrosation5 (starting from 6(7) acetylperimidines) and amination of perimidines 1a—c with sodium azide in PPA with subsequent nitrosation.6 The method suggested in this work has the following ad vantages as compared to those developed earlier. First, it does not require preliminary functionalization of perim idines 1a—c; second, no use of sodium azide in acidic medium is needed and, therefore, no highly toxic and ex plosive HN3 is liberated. Probably, N oxides 4a—c were another reaction products, which were not isolated be cause of their good solubility in water. A suggestion on their formation made based on the Scheme shown below was confirmed by the fact that they were converted to 1,3,6,8 tetraazapyrenes 6a—c by the reduction with zinc dust. The yields of compounds 6a—c starting from perim idines 1a—c were 40—44%. It is probable that the reaction follows the following course. The acetamidation of perimidines 1a—c leads to acetamidamides 2a—c, whose nitrosation8 gives the inter Scheme 1

Reaction of 2-(2-oxo-2,3-dihydro-1H-indol-3-ylidene)acetic acid esters with benzene-1,2-diamine and 2-aminobenzenethiol

Abstract2-(2-Oxo-2,3-dihydro-1H-indol-3-ylidene)acetic acid esters reacted with benzene-1,2-diamine or 2-aminobenzenethiol to give (2-oxo-2,3-dihydro-1H-indol-3-yl)-substituted 3,4-dihydroquinoxalin-2(1H)-ones or 2H-1,4-benzothiazin-3(4H)-ones.

Simple procedure for preparation of quinoxalin-2(1H)-one 3-[Oxo(cyclo)alkyl(idene)] derivatives

A simple preparative procedure was developed for 3-(2-oxoalkylidene)-3,4-dihydroquinoxalin-2(1H)-ones, 4,5-dihydroxy-1-[3-oxo-3,4-dihydroquinoxalin-2(1H)-ylidene]-3,5-octadiene-2,7-dione, and 3-(2,3-dihydroxy-4-methyl-5-oxo-1,3-cyclopentadien-1-yl)quinoxalin-2(1H)-one by reaction of methyl ketones first with diethyl oxalate in the presence of sodium, and then with o-phenylenediamine.

Investigations on 2,3′-biquinolyl series. 20. Novel method for the synthesis of 2,3′-biquinolines by cyclization of β-(2-quinolyl)-2-aminostyrenes

A method has been developed for the synthesis of 2,3′-biquinolines based on the reaction of β-(2-quinolyl)-2-aminostyrenes with acid amides under Vilsmeier reaction conditions.

New three-component reaction of perimidines with sodium azide and sodium nitrite in polyphosphoric acid

Polynuclear aromatic and heteroaromatic compounds, including compounds with peri-annelated pentaand hexa-membered rings, have considerable practical value. Effective medications [1, 2] and luminescent intercalators [3, 4] have been created based on them. We have previously developed a series of methods for peri-annelation of pyrrole [1, 5-7] and furan [5] rings to naphthalene derivatives. At the same time, there are only a few examples of the peri-annelation of the pyrazole nucleus [5, 8]. In the present work, we have developed a method for the synthesis of compounds with such fragments based on the electrophilic amination of arenes with sodium azide in polyphosphoric acid (PPA) [9-11] and nitrosation of the heterocyclic intermediates with sodium nitrite. We have established that heating of the perimidines 1a-c with a threefold excess of sodium azide and a twofold molar excess of NaNO2 in PPA (86% content of P2O5) gave 1,2,5,7-tetraazacyclopenta[cd]phenalenes 2a-c in 46-52% yields. The reaction can be carried with a simultaneous mixture of all components, but in this case the yields are somewhat lower (37-41%). The mechanism of the reaction probably includes the formation of the intermediate compounds 3a-c from the perimidines 1a-c and sodium azide [9-11]. Subsequent nitrosation of these compounds at the nitrogen atom leads to the intermediates 4a-c, which by loss of PPA and a molecule of nitrogen, are converted into the Nnitroso derivatives 5a-c. Cyclization of the latter gives the required compounds 2a-c. H NMR spectra were recorded with a Bruker WP-200 (200 MHz) spectrometer with TMS as internal standard. IR spectra were recorded with a UR-20 spectrophotometer using KBr pellets. The course of the reactions and the purity of the products were monitored by TLC on Silufol UV-254 plates in ethyl acetate. PPA with 86% P2O5 content was prepared by a known method [12]. ______ *To whom correspondence should be addressed, e-mail: alexaks05@rambler.ru.

Chemistry of 2-ylidenefuran-3(2H)-ones: XIX. Reaction of 5-aryl-2(oxoylidene)furan-3(2H)-ones with carboxylic acid hydrazides

Abstract2-[2-(4-Chlorophenyl)-2-oxoethylidene]-5-phenylfuran-3(2H)-one and methyl (5-aryl-3-oxo-2,3-dihydrofuran-2-ylidene)acetates react with carboxylic acid hydrazides to give the corresponding 3-substituted 2-acyl-6-aryl-3-hydroxy-2,3-dihydropyridazin-4(1H)-ones. Specificities of the product structure are discussed.

Investigations on 2,3′-biquinolines 22. Novel and convenient method for the synthesis of benzo[5,6]indolizino-[2,1-b]quinolinium-13-thiolates and benzo-[5,6]indolizino[1,2-c]quinoline-6(5H)-thiones

We have developed a method of synthesis of benzo[5,6]indolizino[2,1-b]quinolinium-13-thiolates and 5,6-dihydrobenzo[5,6]indolizino[1,2-c]quinoline-6-thiones based on the reaction of the corresponding 1′, 2′-dialkyl-1′,2′-dihydro-2,3′-biquinolines and 1′,4′-dialkyl-1′,4′-dihydro-2,3′-biquinolines with sulfur in DMF.

2,6,7-Trihydroxy-4,9-dioxodeca-2,5,7-trienoic and 2-hydroxy-2-(3-hydroxy-4-methyl-2,5-dioxocyclopent-3-en-1-ylidene)acetic acid esters: Synthesis and structural specificity

Claisen condensation of acetone and butan-2-one with diethyl oxalate in the presence of metallic sodium leads to the formation of ethyl 2,6,7-trihydroxy-4,9-dioxodeca-2,5,7-trienoate and ethyl 2-hydroxy-2-(3-hydroxy-4-methyl-2,5-dioxocyclopent-3-en-1-ylidene)acetate, respectively.

Unusual pathway of the reaction of 4-benzoyl-5-phenylfuran-2,3-dione with acetylmethylenetriphenylphosphorane and methyl triphenylphosphoranylideneacetate

Abstract4-Benzoyl-5-phenylfuran-2,3-dione reacts with acetylmethylenetriphenylphosphorane or methyl triphenylphosphoranylideneacetate to form 1:1 adducts of 4-benzoyl-2-hydroxy-2-(2-oxopropyl)-5-phenyl-furan-3(2H)-one or methyl 4-benzoyl-2-hydroxy-3-oxo-5-phenyl-2,3-dihydrofuran-2-ylacetate, respectively, with triphenylphosphine oxide. Structural features of the products are discussed.

Acylpyruvic acid amides and hydrazides: XII. Reaction of 4-Aryl-2-hydroxy-4-oxo-2-butenic acids arylamides with triphenylphosphoranylideneacetic acid esters

Abstract4-Aryl-2-hydroxy-4-oxo-2-butenic (aroylpyruvic) acid arylamides react with triphenylphosphoranylidenacetic acid esters to form products of Wittig reaction at α-carbonyl group, the 5-aryl-3-arylaminocar-bonyl-5-oxo-3-pentenoic acid esters. Features in structure of the obtained compounds are discussed.