Synthesis of 1,3-diazapyrenes from benzo[<Emphasis Type="Italic">f</Emphasis>]quinazolines

Methods have been developed for the synthesis of 1,3-diazapyrenes based on the reactions of 1-methylbenzo[f]quinazolines with DMF dimethyl acetal or with 1,3,5-triazine in PPA. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii. No. 2, pp. 260–262, February, 2009.     

Synthesis of <Emphasis Type="Italic">N</Emphasis>-substituted 1-hydroxypyrrolo[3,4-<Emphasis Type="Italic">f</Emphasis>]indol-5,7-diones

General methods were developed of the synthesis of N-substituted 1-hydroxypyrrolo[3,4-f]indole-5,7-diones using as initial compounds substituted 6-nitroisoindole-1,3-diones and 5-nitro-4-phenacylphtalic acids.     

Ambident chemosensors based on benzo[<Emphasis Type="Italic">h</Emphasis>]chromen-2-one

Schiff bases derived from 7-hydroxy-4-methyl-2-oxobenzo[h]chromene-8-carbaldehyde in solution exist as equilibrium mixtures of benzoid and quinoid tautomers. The fraction of the quinoid tautomer increases with rise in solvent polarity. The Schiff base containing a benzo-15-crown-5 fragment on the nitrogen atom was shown to be a new ambident chemosensor capable of selectively binding transition metal cations via reaction at the o-hydroxyaldehyde imine fragment and alkaline-earth metals via host-guest interaction with the crown ether moiety. This compound exhibits a pronounced sensor activity toward Mg²⁺ and Ba²⁺ ions and is a selective naked-eye fluorescent chemosensor for Cu²⁺ and Co²⁺ ions.     

Synthesis and X-ray study of 6<Emphasis Type="Italic">H</Emphasis>-chromeno[3,4-<Emphasis Type="Italic">e</Emphasis>][1,3,4]triazolo[2,3-<Emphasis Type="Italic">a</Emphasis>]pyrimidine

2-Dimethylamino methylenechromanone 1 reacted with 4H-1,2,4-triazol-3-amine in acetic acid to give only one isolated product which was identified by X-ray study as 6H-chromeno[3,4-e][1,3,4]triazolo[2,3-a]-pyrimidine. The molecular structure of 3, C₁₂H₈N₄O, was determined to be monoclinic, P2₁/c, a = 16.3875(5), b = 8.8378(3), c = 13.8392(5) Å, β = 101.190(1)°, V = 1966.22(11) ų, Z = 8.     

Synthesis of <Emphasis Type="Italic">tert</Emphasis>-butyl 1-(5,8-dioxohexahydro-[1,3]thiazolo[3,4-<Emphasis Type="Italic">a</Emphasis>]pyrazin-3-yl)ethylcarbamate

Two diastereomers of the previously unknown diketopiperazines tert-butyl 1-(5,8-dioxohexahydro-[1,3]thiazolo[3,4-a]pyrazin-3-yl)ethylcarbamate were synthesized and separated by column chro-matography on silica gel. During the cultivation of the crystal of one of compounds, the product was oxidized to corresponding tert-butyl 1-(5,8-dioxo-5,6,7,8-tetrahydro[1,3]thiazolo[3,4-a]pyrazin-3-yl)-ethylcarbamate. The X-ray crystal structure of the latter was established.     

Synthesis of <Emphasis Type="Italic">m</Emphasis>-carborane-C-carboxylic acid hexahydrobenzo[<Emphasis Type="Italic">a</Emphasis>]acridine esters

The possibility was demonstrated of selective preparation of m-carborane-C-carboxylic acid hexahydrobenzo[a]acridine esters both by the reaction of 1,3-diketones with azomethines obtained by condensation of m-carborane-C-carboxylic acid vanillin and vanillal esters with 1- or 2-naphthylamine and by the cascade heterocyclization of 1- or 2-naphthylamine, m-carborane-C-carboxylic acid vanillin and vanillal esters, and CH-acids.     

5,7-Dihydropyrrolo[3,4-<Emphasis Type="Italic">d</Emphasis>][1,2]diazepin-1(2<Emphasis Type="Italic">H</Emphasis>)-ones. Synthesis and transformations

A preparative procedure has been developed for the synthesis of substituted 5,7-dihydropyrrolo-[3,4-d][1,2]diazepines by recyclization of 6-phenylpyrano[3,4-c]pyrrol-4(2H)-one with hydrazine hydrate. The stability of the seven-membered ring in the products under acidic conditions, alkylation, and heteroring fusion to the diazepine ring have been studied.     

Benzo[4,5]imidazo[2,1-<Emphasis Type="Italic">a</Emphasis>]phthalazines: I. substituted <Emphasis Type="Italic">o</Emphasis>-nitrophenylhydrazines in the synthesis of phthalazin-1(2<Emphasis Type="Italic">H</Emphasis>)-ones

Efficient cyclization procedure was developed for 2-nitro-, 2,4-dinitro-, 2-nitro-5-chloro-, and 4,5-dichloro-2-nitrophenylhydrazines with 2-acylbenzoic acids by heating the reagents in a mixture of of concentrated sulfuric acid and ethanol. A series of new phthalazin-1-ones was obtained with a substituted 2-nitrophenyl group in the position 2 and various substituents in the position 4.     

Synthesis and oxidation of vinyl derivatives of <Emphasis Type="Italic">N</Emphasis>-methyl[60]fullereno[<Emphasis Type="Italic">c</Emphasis>]pyrrolidine

Novel organometallic derivatives of N-methyl[60]fullereno[c]pyrrolidine bearing the vinyl fragment at the position 2 of the pyrrolidine ring were synthesized. Their oxidation with 3-chloroperoxybenzoic acid to give N-oxides and epoxides was studied in detail.     

4-hydroxy-2-quinolones 196. synthesis and bromination of 1-allyl-3-(2-hydroxyethyl)-1<Emphasis Type="Italic">h</Emphasis>,3<Emphasis Type="Italic">h</Emphasis>-quinazoline-2,4-dione

The alkylation of 3-(2-hydroxyethyl)-1H,3H-quinazoline-2,4-dione and subsequent bromination of its 1-allyl derivative have been studied. The data obtained has been compared with the results of similar studies on a series of other, related compounds. A rule has been formulated which allows a prediction of 1-allyl-substituted 2-oxo azaheterocycles bromination route based upon the way in which their initial alkylation by allyl bromide in the system DMSO–K₂CO₃ occurs.     

Transformations of 3,3,4-tricyano-3,4-dihydro-2<Emphasis Type="Italic">H</Emphasis>-pyran-4-carboxamides. Synthesis of pyrano[3,4-<Emphasis Type="Italic">c</Emphasis>]pyrrole derivatives

A procedure has been developed for the synthesis of polyfunctional pyrano[3,4-c]pyrrole derivatives via intramolecular cyclization involving vicinal cyano and carboxamide groups on a pyran ring. 3-Amino-1-oxo-1,3a,4,7a-tetrahydropyrano[3,4-c]pyrrole-3a,7a-dicarbonitrile thus obtained react with organic amines to give stable ammonium salts and undergo hydrolysis to 1,3-dioxo-1,2,3,3a,4,7a-hexahydropyrano[3,4-c]pyrrole-3a,7a-dicarbonitriles in the presence of sulfuric acid.     

New Synthesis of Pyrano[4,3-<Emphasis Type="Italic">d</Emphasis>]pyrazolo[3,4-<Emphasis Type="Italic">b</Emphasis>]pyridines

A new efficient method has been developed for the synthesis of highly biologically active pyrano-[4,3-d]pyrazolo[3,4-b]pyridines on the basis of Smiles rearrangement of ethyl [(8-alkyl(aryl)-5-cyano-3,3-dimethyl-3,4-dihydro-1H-pyrano[3,4-c]pyridin-6-yl)oxy]acetates. Intermediate acetohydrazides have also been isolated. The proposed procedure is advantageous due to the possibility of avoiding experimentally difficult chlorination stage.     

Synthesis of oxo derivatives of <Emphasis Type="Italic">N</Emphasis>-(<Emphasis Type="Italic">p</Emphasis>-tolysulfonyl)hexahydrocycloalka[<Emphasis Type="Italic">b</Emphasis>]indoles

Hydroxymercuration-demercuration of N-p-tolysulfonyl-4,4a,9,9a-tetrahydro-3H-carbazoles and N-p-tolyl(or methyl)sulfonyl-1,3a,4,8b-tetrahydrocyclopenta[b]indoles leads to the formation of the corresponding N-p-tolylsulfonyl-2,3,4,4a,9,9a-hexahydro-1H-carbazol-2-ols and N-p-tolyl(or methyl)sulfonyl-1,2,3,3a,4,8b-hexahydrocyclopenta[b]indol-2-ols. The latter are oxidized to 2-oxo derivatives with potassium dichromate. The oxidation of 2-methoxy-8-methyl-N-p-tolylsulfonyl-2,3,4,4a,9,9a-hexahydro-1H-carbazol-1-ol under analogous conditions gives 2-methoxy-8-methyl-N-p-tolysulfonyl-2,3,4,4a,9,9a-hexahydro-1H-carbazol-1-one.     

Alkylation of 3-methyl-1<Emphasis Type="Italic">H</Emphasis>-acenaphtho[5,6-<Emphasis Type="Italic">de</Emphasis>]pyridazine

Alkylation of 3-methyl-1Н-acenaphtho[5,6]pyridazine with methyl and propyl iodides as well as with benzyl chloride in alkaline medium leads to the formation of the corresponding both N- and С-substituted pyridazine derivatives and also to the dimerization product of the initial compound. The ratio of obtained compounds depends on the used hydride, reaction temperature, and solvent.     

7,8,9-trimethyl-1-phenyl-3<Emphasis Type="Italic">H</Emphasis>-pyrrolo[2,1-<Emphasis Type="Italic">d</Emphasis>][1,2,5]triazepin-4(5<Emphasis Type="Italic">H</Emphasis>)-one. Synthesis and reactions

A strategy was developed for the synthesis of 7,8,9-trimethyl-1-phenyl-3H-pyrrolo[2,1-d][1,2,5]-triazepin-4(5H)-one, reactions of its functionalization at the С⁴ atom and aza rings fusion at the С⁴?N³ bond were explored. The formation mechanism of the pyrrolo-1,2,5-triazepinone scaffold was suggested.     

Synthesis of 6-methyl-8<Emphasis Type="Italic">H</Emphasis>-dibenzo[<Emphasis Type="Italic">a</Emphasis>,<Emphasis Type="Italic">g</Emphasis>]quinolizin-8-imines <Emphasis Type="Italic">via Reissert</Emphasis> compounds

Alkylation of Reissert compounds derived from 3-methylisoquinolines with several 2-cyanobenzylbromides followed by hydrolytic cleavage provided the corresponding 1-benzyl-3-methylisoquinolines. Treatment of the latter with methylmagnesiumiodide caused cyclization to the title compounds rather than formation of 2-acetylbenzylisoquinolines.     

<Emphasis Type="Italic">Z</Emphasis>-and <Emphasis Type="Italic">E</Emphasis>-conformers of <Emphasis Type="Italic">N</Emphasis>-chloroacetylcytisine

N-Chloroacetylcytisine was synthesized by acylation of (–)-cytisine. Stable Z- and E-conformers with respect to rotational isomerism around the N-12–CO bond were found in PMR spectra at room temperature. The point at which PMR resonances of the Z- and E-conformers coalesced upon heating was measured. The transition barrier between the conformers was estimated.     

Synthesis of 2<Emphasis Type="Italic">N</Emphasis>-Alkyl-substituted 5-Amino-3-imino-1,2,4-thiadiazolines

Conditions for an efficient and a readily reproducible synthesis of a series of 2N-Alkyl-substituted 5-amino-3-imino-1,2,4-thiadiazolines by the direct alkylation of 3,5-diamino-1,2,4-thiadiazole with alkyl bromides in fairly high yields (up to 76%).