Fused s-triazino heterocycles. XIV 8H-1,3,7,8,9,10c-hexaazacyclopenta[a]phenalene, 1,3,7,8,10,11c-hexaazabenz[de]anthracene and 13H-4,6,8,13a, 13c-pentaazabenzo[de]naphthacene,three new ring systems

The synthesis of the title compounds 3,4 and 5 is described, using 7,9-dibromo-5-tribromomethyl-2-t-butyl-4-cyano-1,3,6,9b-tetraazaphenalene 2a as starting material. The key intermediates are 7,9-dibromo-2-t-butyl-4-cyano-5-hydrazino-1,3,6,9b-tetraazaphenalene 2b , 5-benzamidino-7,9-dibromo-2-t-butyl-4-cyano-1,3,6,9b-tetraazaphenalene 2c , and 7,9-dibromo-2-t-butyl-5-(2-carboxyanilino)-4-cyano-1,3,6,9b-tetraazaphenalene 2e.     

Fused s-triazino heterocycles. XVI. 13H-1,3,7,8,12a, 13c-hexaazabenzo[de]naphthacene and 1,3,7,8,11b, 12,14,14d-octaazadibenzo[de,hi]naphthacene,two new ring systems

The reaction of 7,9-dibromo-5-tribromomethyl-2-t-butyl-4-cyano-1,3,6,9b-tetraazaphenalene ( 1a ) with 2-amino-5-picoline is shown to give 4,6-dibromo-2-t-butyl-13-imino-11-methyl-13H-1,3,7,8,12a,13c-hexaazabenzo[de]naphthacene ( 3 ) and the isomeric 7,9-dibromo-2-t-butyl-4-cyano-5N-(5-methyl-2-pyridyl)amino-1,3,-6,9b-tetraazaphenalene ( 2a ). A related annulation reaction of 7,9-dibromo-2-t-butyl-5-chloro-4-cyano-1,3,6,9b-tetraazaphenalene ( 1g ) with 2-amino-6-trimethylacetamidopyridine leads in two steps to 4,6-dibromo-2,13-di-t-butyl-1,3,7,8,11b,12,14,14d-octaazadibenzo[de,hi]naphthacene ( 4a ). The preparation of 1g , 5-azido-7,9-dibromo-2-t-butyl-4-cyano-1,3,6,9b-tetraazaphenalene ( 1c ) and the reaction of the latter with pyrrolidine leading to 7,9-dibromo-2-t-butyl-4-cyano-5-(1-pyrrolidino)-1,3,6,9b-tetraazaphenalene ( 1e ) are also reported. Attempted displacement of the azido-group on 1c by 2,6-diaminopyridine affords surprisingly 5-amino-7,9-dibromo-2-t-butyl-4-cyano-1,3,6,9b-tetraazaphenalene ( 1d ).     

Fused s-triazino heterocycles. XVII. 8,13-Dihydro-1,3,7,8,13c-pentaazabenzo[de]naphthacene, 7H-1,3,7,8,11b,12,14-heptaazadibenzo[de,hi]naphthacene and 8H-1,3,7,8,13,14c-hexaazabenzo[4,5]cyclohepta[1,2-a]phenalene,three new ring systems

The reaction of 7,9-dibromo-5-tribromornethyl-2-t-butyl-4-cyano-1,3,6,9b-tetraazaphenalene ( 1a ) with p-toluidine is shown to give 4,6-dibromo-2-t-butyl-8,13-dihydro-13-imino-11-methyl-1,3,7,8,13c-pentaazabenzo[de]naphthacene ( 4 ) in two steps with 7,9 dibromo-2-t-butyl-4-cyano-5-p-toluidino-1,3,6,9b-tetraazaphenalene ( 2b ) as the intermediate product. A related annulation reaction of 1a with N-(5-amino-2,4-dimethylphenyl)trimethylacetamide ( 8 ) leads in two steps to 9,11-dibromo-2,13-di-t-butyl-4,6-dimethyl-7H-1,3,7,8,11b,12,14-heptaazadibenzo[de,hi]naphthacene ( 6 ) with 7,9-dibromo-2-t-butyl-4-cyano-5N-(2,4-dimethyl-5-trimethylacetamidophenyl)amino-1,3,6,9b-tetraazaphenalene ( 2d ) as the intermediate product. In a similar fashion the reaction of 1a with o-phenylenediamine forms 14-amino-4,6-dibromo-2-t-butyl-8H-1,3,7,8,13,14c-hexaazobenzo[4,5]cyclohepta[1,2-a]-phenalene ( 12 ) by way of the intermediate 5-N-(2-aminophenyl)amino-7,9-dibromo-2-t-butyl-4-cyano-1,3,6,9b-tetraazaphenalene ( 2e ). The preparation of N-(2,4-dimethyl-5-nitrophenyl)-trimethylacetamide ( 11 ) and its reduction to N-(5-amino-2,4-dimethylphenyl)trimethylacetamide ( 8 ) is also described.     

Fused s-triazino heterocycles. XVIII. 1,3,4,7,11c-Pentaazabenz[de]anthracene and 1,3,4,6,7,11c-hexaazabenz[de]anthracene. Two new ring systems

The reaction of 2-amino-4-chloro-6-methylpyrimidine ( 3a ) with trimethylacetyl chloride gave 4-chloro-6-methyl-2-trimethylacetamidopyrimidine ( 5 ). This latter compound with excess anthranilonitrile gave in one step 2-t-butyl-5-methyl-1,3,4,7,11c-pentaazabenz[de]anthracene ( 6a ). To prepare 2-t-butyl-5-dimethylamino-1,3,4,6,7,11c-hexaazabenz[de]anthracene ( 6b ) it was found necessary to first react 2-amino-4-chloro-6-dimethylamino -5 -triazine ( 3b ) with anthranilonitrile to yield the intermediate product 2-amino-4(2-cyanoanilino)-6-dimethylamino-s-triazine ( 4 ). Reaction of the latter with trimethylacetyl chloride gave 6b .     

Fused s-triazino heterocycles. XIII. 1,3,7,10,11c-Pentaazabenz[de]-anthracene and 1,3,7,10,11,13,13d-heptaazabenz[de]cyclopenta[H]-anthracene,two new ring systems

The synthesis of the title compounds 5a-c and 6a-c is described using, 2,6-diaminopyridine as starting material. The key intermediates are 2-t-butyl-4-cyano-5(2-dimethylaminoethenyl)-1,3,6,9b-tetraazaphenalene 4 and 10-amino-2-t-butyl-10,11-dihydro-11-imino-1,3,7,10,11c-pentaazabenz[de]anthracene 5c .     

Fused-s-triazino heterocycles. XII. 13H-4,6,7,8,13a, 13c-hexaazabenzo-[de]naphthacene,a new ring system

The synthesis of the titled compound is described using 5-(2-carboxyanilino)-2-methyl-1,3-4,6,9b-pentaaza-phenalene as starting material.     

Fused 1,2,4-triazole heterocycles. IV. Synthesis of four new heterocyclic ring systems of [1,2,4]triazolo[1,3]thiazinoquinolines

Syntheses of 5H-[1,2,4]triazolo[5′,1′:2,3][1,3]thiazino[5,4-c]quinolines 8, 5H-[1,2,4]triazolo[3′,4′:2)3][1,3]thiazino[5,4-c]quinolines 9, 5H-[1,2,4]triazolo[5′,1′:2,3][1,3]thiazino[5,6-c]quinolines 14 and 5H-[1,2,4]triazolo[3′,4′:2,3][1,3]thiazino[5,6-c]quinolines 15 are described starting from 4-chloro-3-chloromethylquinaldine (4) and 1,2,4-triazole-5-thiols 5 taking advantage of different reactivity of the chlorine atoms of 4 under different reaction conditions. The structures of products 8, 9, 14 and 15 and the intermediates leading to them were confirmed by desulfurization, unequivocal syntheses and nmr spectroscopy as well.     

Fused s-triazino heterocycles. VIII. 1,3,4,6,9b-pentaazaphenalenes. Reactions of a methyl and bromomethyl side chain

Enhanced reactivity of the methyl group of 2-t-butyl-5-methyl-1,3,4,6,9b-pentaazaphenalene allowed acetic anhydride-catalyzed condensation reactions with several aromatic aldehydes, and base-catalyzed alkylation reactions with several alkyl halides to take place, albeit in low yields. Of the many nucleophiles tried, only salts of carboxylic acids, in the presence of 18-crown-6, were able to displace bromine from 2-(bromomethyl)-5-methyl-1,3,4,6,9b-pentaazaphenalene.     

Polycondensed nitrogen heterocycles. X. 5,6,7,8-Tetrahydropyrrolo[1,2-e][1,5]benzodiazocin-7-ones. A new ring system

The synthesis of a new heterocyclic ring system is described. Condensation of 1,4-diketones 1a,b with β-alanine gave the substituted propionic acids 2a,b which upon reduction with palladium on charcoal afforded compounds 3a,b . Title compounds 4a,b were obtained by refluxing 3a,b in toluene with p-toluenesulphonic acid as catalyst.     

Synthesis of pentacyclic 13-azadibenzo[a,de]anthracenes via anionic cascade ring closure

Bromine-lithium exchange using tert-butyllithium at -78 degrees C initiates a cascade process whereby either xanthone derivatives or pentacyclic 13-azadibenzo[a,de]anthracenes are produced in high yields. The reaction proceeds via a sequential intramolecular trapping of organolithium intermediates.     

Dicyclobuta[de,ij]naphthalene and dicyclopenta[cd,gh]pentalene: a theoretical study

The structures, energetics, and aromatic character of dicyclobuta[de,ij]naphthalene, 1, dicyclopenta[cd,gh]pentalene, 2, dihydrodicyclobuta[de,ij]naphthalene, 3, and dihydrocyclopenta[cd,gh]pentalene, 4, have been examined at the B3LYP/6-311++G//B3LYP/6-31G level of theory. All molecules are bowl-shaped, and the pentalene isomers, 2 and 4, are most stable. A comparison with other C(12)H(6) and C(12)H(8) isomers indicates that 2 is approximately 25 kcal/mol less stable than 1,5,9-tridehydro[12]annulene and 4 is approximately 100 kcal/mol higher in energy than acenaphthylene, both of which are synthetically accessible. The transition state structure for bowl-to-bowl inversion of 1 is planar (D(2)(h)()) and lies 30.9 kcal/mol higher in energy than the ground state; the transition state for inversion of 2 is C(2)(h)() and lies 46.6 kcal/mol higher in energy. Symmetry considerations, bond length alternations, and NICS values (a magnetic criterion) all indicate that the ground states of 1, 3, and 4 are very aromatic; however, HOMA values (a measure of bond delocalization) indicate that 3S and 4S are aromatic but that 1S is less so. NICS values for the ground state of 2 strongly indicate aromaticity; however, bond localization, symmetry, and HOMA values argue otherwise.     

Eight-membered organosulfur heterocycles. Synthesis of dibenzo[d,g][1,3,6,2]dioxathiaphosphocin and dibenzo[d,g][1,3,6,2]dioxathiasilocin ring systems

The reaction of 2,2′-thiobisphenols with either phenylphosphonous dichloride or phosphorus trichloride followed by an alcohol gave derivatives of the dibenzo[d,g][1,3,6,2]dioxathiaphosphocin ring system. The analogous reaction of 2,2′-thiobisphenols with alkyl and aryl dichlorosilanes gave the heretofore unreported dibenzo[d,g][1,3,6,2]dioxathiasilocin ring system. The analytical and spectral data are reported.     

1H and 13C NMR signal assignments of some new spiro[7H-benzo[de]anthracene-naphthopyrans

The complete 1H and 13C NMR signal assignment of four new photochromic spiro[7H-benzo[de]anthracene-naphthopyrans] was achieved using one- and two-dimensional methods (DEPT, COSY, HSQC, HMBC, NOESY).     

Polycondensed nitrogen heterocycles. Part 17. Isoxazolo[4,3-d]pyrazolo[3,4-f][1,2,3]triazepine. A new ring system

The title compounds were prepared by nitration of compounds 2 , reduction of the dinitro derivatives 4 and diazotization of the diamino derivatives 6 followed by an intramolecular coupling reaction. Compound 4a showed good activity against Salmonella cholerasuis and Clostridium perfringens bacteria.     

Pyridazines. XXXVIII. Pyrrolo[1,2-b] pyridazines and 4H-4a,7b-diazacyclopent[cd] indenes

Pyrrolo[1,2-b] pyridazines have been prepared and investigated for electrophilic substitutions. Depending on the electrophile and reaction conditions, mono, di, tri or tetrasubstituted derivatives were formed. Some investigations are reported also for the related 4H-4a,7b-diazacyclopent[cd]-indenes.     

Novel heterocycles. 13 Synthesis of 5,6-dihydro-1H-3H-pyrrolo[3,2,1-ij][3,1]benzoxazine-1,3-dione

The synthesis of 5,6-dihydro-1H,3H-pyrrolo[3,2,1-ij][3,1]benzoxazine-1,3-dione ( 2a ), a new ring system, from N-acetylindoline is described.