Synthesis of regioisomeric 6,9-(chlorofluoro)-substituted benzo[g]quinoline-5,10-diones,benzo[g] isoquinoline-5,10-diones and 6-chloro-9-fluorobenzo[g]quinoxaline-5,10-dione

Treatment of difluoro or chloro fluoro-substituted benzyl bromides 5a-c with zinc dust in tetrahydro-furan leads to the corresponding benzylic zinc bromides 6a-c. These organometallics on treatment with chlorosubstituted heterocyclic esters 4A and 4B mediated by nickel catalysis undergo couplings to yield dihalobenzyl substituted heterocyclic esters 7Aa-c and 7Ba-c. Treatment of 4c with 6c under Pd catalysis leads to 7Cc. The acids 8, prepared by hydrolysis of these esters, with treatment of fuming sulfuric acid undergo cyclizations and oxidations to yield the desired regioisomeric dihalo-substituted heterocyclic quinones 2.     

Heterocyclic quinones with bridgehead nitrogen atoms. Part I. Pyrrolo[1,2-a]quinoxaline-6,9-dione and pyrrolo[2,1-c][1,2,4]benzotriazine-6,9-dione

The synthesis and some reactions of pyrrolo[1,2-a]quinoxaline-6,9-dione and pyrrolo[2,1-c][1,2,4]benzotriazine-6,9-dione are described.     

Nitration studies of naphtho[2,3-c][1,2,5]thiadiazole

Nitration of naphtho[2,3-c][1,2,5]thiadiazole gives the 5-nitro derivative in 61–66% yield. Chlorination of this product apparently gives an unstable addition product which loses hydrogen chloride on recrystallization to give 4-chloro-8-nitronaphtho[2,3-c][1,2,5]thiadiazole. Thus, naphtho[2,3-c][1,2,5]thiadiazole under nitrating conditions behaves as a 2-substituted naphthalene rather than as an anthracene analog.     

Synthesis of 4-hydroxy-6,9-difluorobenz[g]isoquinoline-5,10-diones and conversions to 4-hydroxy-6,9-bis[(aminoalkyl)amino]-benz[g]isoquinoline-5,10-diones

Synthetic procedures have been developed which lead to 4-hydroxy-6,9-difluorobenz[g]isoquinoline-5,10-dione ( 4a ) and its 3-methyl analogue 4b . Attempts to displace the fluorides from 4a with N,N-dimethylethylenediamine were unsuccessful. Analogue 4a on treatment with N-(t-butoxycarbonyl)ethylene diamine led to 15 , formed from addition of the nucleophilic amine to C-3. On the other hand, analogue 4b , on treatment with N,N-dimethylethylenediamine led to the anticipated difluoride displacement product 3c . The protection of the hydroxy group of 4a by benzylation with phenyldiazomethane led to 4c which on treatment with N-(t-butoxycarbonyl)ethylene diamine or N,N-dimethylethylenediamine led to the corresponding 6,9-bis-substituted analogues 18a and 18b , respectively. Reductive debenzylations of 18a and 18b by hydrogenation over Pearlman's catalyst also effected partial reductions of the quinone. However, air oxidation of the over reduced products led to 3a and 3b , respectively. Treatment of 3a with hydrogen chloride gas led to the hydrochloride salt of 3d . Addition of O-p-Methoxybenzyl-N,N'-diisopropylurea to 4a led to the p-methoxybenzyl analogue 4d . Treatment of 4d with N,N-dimethylethylene diamine or N-(t-butoxycarbonyl)ethylene diamine led to displacements of the fluorides to yield 18c and 18d , respectively. Deprotection of 18c to 3b was accomplished using methanesulfonic acid. Treatment of 18d with trifluoroacetic acid followed by addition of maleic acid led to dimaleate salt of 3d .     

Naphthomoles. 7. Synthesis of 4,11-dimethoxynaphtho[2,3-f]indole-5,10-dione and 4-methoxynaphtho[2,3-f]-indole-5,10-dione

4,11-Dimethoxynaphtho[2,3-f]indole-5,10-dione and 4-methoxynaphtho[2,3-f[indole-5,10-dione have been synthesized by the Leimgruber-Batcho reaction from 1,4-dimethoxy-2-methyl-3-nitroanthraquinone.Russian University of Chemical Technology, Moscow 125190. Center for Drug Chemistry, All-Russian Scientific Research Institute for Pharmaceutical Chemistry, Moscow 119815. Translated from Khimiya Geterotsklicheskikh Soedinenii, No. 8, pp. 1050–1054, August, 1996. Original article submitted March 20, 1996.     

The synthesis of 6,9-difluorobenzo[g]quinoline-5,10-dione. Displacements of the fluorides by diamines which lead to 6,9-bis[(aminoalkyl)amino]benzo[g]quinoline-5,10-diones

The synthesis of 6,9-difluorobenzo[g]quinoline-5,10-dione ( 3b ) is described. Facile ipso substitutions of the fluorides from 3b by diamines readily yield the corresponding 6,9-bis[(aminoalkyl)amino]benzo-[g]quinoline-5,10-diones 2 . The analogue 2d has been synthesized by side arm modifications of dione 8a .     

Heterocyclic analogs of 5,12-naphthacenequinone. 2. Synthesis of 4,11-dihydroxynaphtho[2,3-f]indazole-5,10-dione and its n-methyl derivatives

On methylating 4,11-dimethoxynaphtho[2,3-f]indazole-5,10-dione with methyl iodide in the presence of base a mixture is formed of its 1-and 2-methyl derivatives. Demethylation of the methoxy groups of the starting material and of the products of its alkylation leads to the formation of 4,11-dihydroxynaphtho[2,3-f]indazole-5,10-dione (pyrazoloquinizarine) and its 1-and 2-methyl derivatives. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 691–696, May, 2006.     

The synthesis of 6,9-bis[(aminoalkyl)amino] substituted benzo[g]quinoxaline-, benzo[g]quinazoline- and benzo-[g]phthalazine-5,10-diones via regiospecific displacements

The synthesis of 6,9-difluoro substituted benzo[g]quinoxaline-5,10-diones ( 3A ), benzo[g]quinazoline-5,10-diones ( 3B ) and benzo[g]phthalazine-5,10-diones ( 3C ) have been accomplished. Treatment of 3A, 3B or 3C with diamines or N-(t-butoxycarbonyl)ethylenediamine led to the corresponding 6,9-bis[(aminoalkyl)amino]-substituted analogues related to 2A, 2B and 2C , respectively. The mono-substituted derivatives 4h and 4i could be isolated from displacements commencing from 3A . A competitive ring-opening of the pyrimidine ring of 2C occurred during the reaction with N,N-dimethylethylenediamine. Removal of the BOC-protecting group from 2Ac led to the hydrochloride salt 2Ab . A novel synthetic pathway to 6,9-dihydroxybenzo[g]-phthalazine-5,10-dione ( 21a ) was developed. Conversion of 21a to the ditosylate 21b was readily accomplished. Treatment of 21b with N,N-dimethylethylenediamine or N-(t-butoxycarbonyl)ethylenediamine led to 2Ca and 2Cc , respectively. Removal of the BOC-protecting group from 2Cc with trifluoroacetic acid followed by ion-exchange led to the hydrochloride salt 2Cb . Treatment of ditosylate 21b with N-(t-butoxycar-bonyl)ethylenediamine also led to the mono-substituted analogue 25a along with a small amount of the O-S cleavage product 25b . Treatment of 25a with N,N-dimethylethylenediamine led to the unsymmetrically substituted derivative 25c which was converted into the trifluoroacetate salt 25d.     

Efficient Red Electroluminescence From Phenanthro[9,10-d]imidazole-Naphtho[2,3-c][1,2,5]thiadiazole Donor-Acceptor Derivatives

Red emission is one of the three primary colors and is indispensable for full color displays. Fluorescent materials that can generate efficient red electroluminescence (EL) are limited and need to be developed. In this work, we report efficient red emitters based on phenanthro[9,10-d]imidazole-naphtho[2,3-c][1,2,5]thiadiazole donor-acceptor derivatives. The molecules, abbreviated as PINzP and PINzPCN, exhibited high photoluminescence quantum yield (PLQY) up to unity in doped films. They can also reach a relatively high PLQY of ∼30% in neat films. PINzP and PINzPCN were capable of generating efficient red EL in doped devices with a maximum external quantum efficiency (EQE) of 6.96% and 5.92%, respectively.     

Naphthoindazoles. Synthesis of 4,11-Dimethoxynaphtho[2,3-f]indazole-5,10-dione

The previously unknown 4,11-dimethoxynaphtho[2,3-f]indazole-5,10-dione has been obtained by the thermal cyclization of N-nitroso derivative of 2-acetamido-3-methyl-1,4-dimethoxyanthraquinone.     

Halogenation and nitration of naphtho[1,2-c][1,2,5]thiadiazole

Bromination of naphtho[1,2-c][1,2,5]thiadiazole ( I ) gives either an addition product, 4,5-dibromo-4,5-dihydronaphtho[1,2-c][1,2,5]thiadiazole ( II ), or a substitution product, 5,6-dibromonaphtho[1,2-c][1,2,5]thiadiazole ( III ), depending on the reaction conditions. Dehydrobromination of II gives 5-bromonaphtho[12-c][1,2,5]thiadiazole ( IV ). Chlorination of I gives the corresponding addition product V or 5-chloronaphtho[1,2-c][1,2,5]thiadiazole ( VI ). Compound VI can also be obtained by dehydrochlorination of V. The nitration of I produces a mixture of isomeric substitution products, 9-nitro VIII and 6-nitronaphtho[1,2-c][1,2,5]thiadiazoles ( VII ).     

Synthesis and photochemical properties of phenoxy derivatives of anthra[2,3-b]furan-5,10-dione

Nucleophilic replacement of the hydroxy groups in ethyl 4,11-dihydroxy-2-methyl-5,10-dioxo-5,10-dihydroanthra[2,3-b]furan-3-carboxylate by chlorine upon treatment with phosphorus acid chlorides gave the corresponding 4(11)-chloro derivatives which were converted into photochromic ethyl 4(11)-phenoxy-2-methyl-5,10-dioxo-5,10-dihydroanthra[2,3-b]furan-3-carboxylates. Photoinduced decomposition of the latter leads to the formation of phenol and fluorescent hydroxyanthra[2,3-b]furandiones.     

1,2,5]Thiadiazolo[3,4-c][1,2,5]thiadiazolidyl: a long-lived radical anion and its stable salts

[1,2,5]Thiadiazolo[3,4-c][1,2,5]thiadiazole (1) is synthesized in 62% yield by fluoride ion-induced condensation of 3,4-difluoro-1,2,5-thiadiazole with (Me(3)SiN=)(2)S. The reversible electrochemical reduction of 1 leads to the long-lived [1,2,5]thiadiazolo[3,4-c][1,2,5]thiadiazolidyl radical anion (2) and further to the dianion (3). The radical anion 2 is also obtained by the chemical reduction of the precursor 1 with t-BuOK in MeCN. The radical anion 2 is characterized by ESR spectroscopy in solution and in the crystalline state. The stable salts [K(18-crown-6)][2] and [K(18-crown-6)][2].MeCN (8 and 9, respectively) are isolated from the spontaneous decomposition of the [K(18-crown-6)][PhXNSN] (6, X = S; 7, X = Se) salts in MeCN solution followed by XRD characterization. The radical anion 2 acts as a bridging ligand in 8 and as chelating ligand in 9. The structural changes observed by XRD in going from 1 to 2 are explained by means of DFT/(U)B3LYP/6-311+G calculations.     

A new derivative of 1,5-dihydropyrazolo[4,3-c][1,2,5]benzotriazepine

A new compound, 1,5-dihydro-3-methyl-7-nitro-propylpyrazolo[4,3-c][1,2,5]benzotriazepine, was synthesized by intramolecular cyclization of 5-amino-4-[(2-bromo-5-nitrophenyl) azo]-3-methyl-1-isopropylpyrazole, and it was established on the basis of the spectral data that the triazepine ring in the synthesized compound exists in two tautomeric forms — amino-azo- and hydrazone. The structure of the compound synthesized was confirmed by the data of the PMR, IR, electronic, and mass spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1136–1139, August, 1984.     

Pyrrolo[3,2-c][1,2,5]benzotriazocine: A new ring system

A nucleophilic substitution reaction in the pyrrole series, achieved by a neutral nucleophile, led to the key intermediate 7 which by reduction and successive diazotization afforded the new ring system pyrrolo[3,2-c][1,2,5]benzotriazocine 9 in good yield.     

Synthesis of thieno[3,4-c] and thieno[3,2-c][2,1]benzothiazepines

Starting from [4,3-c] and [3,2-c] methyl chlorosulfonylthiophenecarboxylates the synthesis of ketones 7 and 8 is described. These compounds are the first two representatives of the new thieno[3,4-c] and thieno-[3,2-c][2,1]benzothiazepine ring systems. The formation of methyl 3-chlorosulfonylthiophene-2-carboxy-late is also revised.