Chemistry of isoindolines. The synthesis of 1,2,3,5,6,7-Hexahydrobenzo[1,2-c: 4,5-c′]dipyrrole and 1,2,3,4,5,6-Hexahydrobenzo[1,2-c: 3,4-c′]dipyrrole

The preparation and properties of 1,2,3,5,6,7-hexahydrobenzo[1,2-c: 4,5-c′]dipyrrole (I) and its isomer, 1,2,3,4,5,6-hexahydrobenzo[1,2-c:3,4-c′]dipyrrole (II), are described. Contrary to the claims of earlier investigators, compound I and its 2,6-diacetyl and 2,6-dicarboxarnide derivatives VI and IX are easily preparable, readily isolable, stable substances.     

Picryl derivatives of benzo[1,2-d:4,5-d′]bistriazole and benzo[1,2-d:4,5-d′]bistriazole-4,8-dione

In a previous communication from this laboratory it was reported that benzotriazole reacts with both picryl chloride and picryl fluoride to give 1-picrylbenzotriazole exclusive of any 2-picrylbenzotriazole (3). As an extension of this study we have examined the reactions of benzo[1,2-d:4,5-d′]bistriazole (I) and benzo[1,2-d:4,5-d′]bistriazole-4,8-dione (II) with picryl fluoride.     

Furopyridines. XXIX. Reactions of furo[2,3-b:4,5-c‘]-, -[3,2-b:-4,5-c’]-, -[2,3-c:4,5-c‘]- and -[3,2-c:3,2-c’]dipyridine

Furo[2,3-b:4,5-c‘]- 1a , -[3,2-b:4,5-c’]- 1b , -[2,3-c:4,5-c‘]- 1c and -[3,2-c:4,5-c’]dipyridine 1d were derived to the N-oxides 2a-d , N‘-oxides 2′b , 2′c or N,N’-dioxide 3b-d by N-oxidation with m-chloroperbenzoic acid. Chlorination of these N-oxides, N′-oxide and N,N′-dioxides with phosphorus oxychloride afforded compounds chlorinated at the α-position(s) to the ring nitrogen 4a-d , 4′c , 14b-d and 14′b . Acetoxylation of N-oxides 2a-d and 2′c with acetic anhydride gave the corresponding pyridone compounds 6a-d and 6′c in good yields, while the acetoxylation of N,N′-dioxides gave a complex mixture from which no compound could be isolated. Cyanation of 2a-d, 2′c and 3b-d with trimethylsilyl cyanide yielded the cyano compounds 7a-d , 7′c , cyano-N-oxides 15b-d and dicyano compounds 15′c and 15′d . Monocyano compounds 7a-d and 7′c were converted to the imino esters 8a-d and 8′c by treatment with sodium ethoxide. Imino esters were derived to the carboxylic esters 9a-d and 9′c , from which the corresponding alde hydes 10a-d and 10′c were obtained by reduction with diisobutylaluminum hydride. Dicyanide 15′c was converted to dialdehyde 19 by the treatment with sodium ethoxide, and the subsequent hydrolysis of the imino ester and reduction of the carboxylic ester with diisobutylaluminum hydride.     

Heterocyclic fused tropylium ions VII. On the synthesis of 9H-dithieno[2,1 -b:4,5-c′]tropylium fluoborate and 4H-dithieno[1,2-b:4,5-c′]tropylium fluoborate

9H-Dithieno[2,1 -b:4,5-c′]tropylium ion (III) and 4ii-dithieno[1,2-b:4,5-c′]tropylium ion (IV) have been synthesized by ring-closure of 1-(4-carboxy-3-thienyl)-2-(3′-thienyl)ethane (IX) and 1-(4-carboxy-3-thienyl)-2-(2′-thienyl)ethane (XVI), respectively, followed by bromination-debrom-ination to 9H-cyclohepta[2,1-b:4,5-c′] dithiophen-9-one (XI) and 4H-cyclohepta[1,2-b:4,5-c′]-dithiophen-4-one (XVIII), and finally by reduction and hydride transfer. The tropylium ions III and IV were less stable than the [b,b′]-fused isomers previously studied.     

Conversion of 3,7-Dialkoxy-4H,8H-benzo[l,2-c:4,5-c']diisoxazole-4,8-dione into new heterocyclic systems

Treatment of 1a or 1b with concentrated acids yielded the acid 3 , with alkali hydrogen carbonates the sodium salt 7 and the potassium salt 8 ; by reacting with phosphorus pentachloride the vinylogous acid chloride 9 was isolated. Reactions of 9 with amines such as N-nucleophiles led to the corresponding amides 10, 11, 14, 15 , and with alcohols such as O-nucleophiles to the corresponding alkoxyderivatives 16a, 16b , which are isomeric compounds to 1a, 1b and 2a, 2b.     

The chemistry of 1,2,5-thiadiazoles,IV. Benzo[1,2-c:3,4-c′:5,6-c″] tris [1,2,5] thiadiazole

Benzo [1,2-c:3,4-c′:5,6-c″] tris [1,2,5] thiadiazole (1) was synthesized from benzo [1,2-c:3,4-c′] - bis [1,2,5] thiadiazole (11) . Nitration of 11 gave compound 15 , which on direct amination gave nitroamine 17 . Reduction of 17 gave diamine 18 , and cyclization of 18 with thionyl chloride gave 1 . Diamine 18 was also cyclized with selenium oxychloride, glyoxal, 9,10-phenanthrene-quinone, and formic acid to give the compounds 4, 5, 19 , and 6 , respectively. A new procedure for the preparation of 2,1,3-benzothiadiazole (7) from o-phenylenediamine was used.     

Zum Reaktionsverhalten des polycyclischen Oligoalumosiloxans [Ph2SiO]8[AlO(OH)]4 gegenüber Hexamethyldisilazan

The Reaction Behaviour of the Polycylic Oligoalumosiloxane [Ph₂SiO]₈[AlO(OH)]₄ towards Hexamethyldisilazane The reaction of the oligoalumosiloxane [Ph₂SiO]₈[AlO(OH)]₄ ( 1 ) with hexamethyldisilazane leads to the triple ionic [Ph₂SiO]₈[AlO₂]₂[AlO(O‐SiMe₃)]₂[NH₄·THF]₂·2 THF ( 2 ) and in the presence of pyridine to [Ph₂SiO]₈[AlO_1.5]₄·2py·1.5 C₇H₈ ( 3 ). Apart from the usual characterization techniques (NMR and IR spectroscopy) the molecular structures of 2 and 3 have been determined by single‐X‐ray diffraction analyses. Both alumosiloxanes 2 and 3 present new types of molecular structures with a central four membered Al₂O₂‐ring, on which the further aluminium atoms are attached via oxygen atoms. This leads to an Al₄‐lozenge, which is centered in subtriangles by oxygen atoms.     

Zum Reaktionsverhalten chlorsubstituierter Methanphosphonsäuredialkylester gegenüber Trialkylphosphiten,Dialkylphosphiten und Alkohol/Natriumalkoholat

On the Reaction of Chloro-substituted Methane Phosphonic Acid Dialkylester with Dialkylphosphites, Trialkylphosphites, or Alcohol/Sodium Alcoholate Dialkylesters of trichloromethane phosphonic acid react analogous to carbon tetrachloride with dialkylphosphites and alcohol in the presence of tertiary amines or with trialkylphosphites and alcohol yielding diesters of dichlormethane phosphonic acids and triesters of phosphoric acid. When esters of trichlormethane or dichloromethane phosphonic acid react with alcohols in the presence of sodium alcoholates a quantitative cleavage of P? C bond occurs and triesters of phosphoric acid and CHCl₃ or CH₂Cl₂ are formed.     

Polyazasteroids II.. 1,2,4-Triazolol[3′,4′:2,3]pyrimido[4,5-c]quinolin- 11(12H)ones,imidazo[2′,1′:2,3]pyrimido[4,5-c]quinolin-11(12H)ones and 2,3-dihydroimidazo[2′,1′:2,3] pyrimido[4,5-c]quinolin-11(12H)ones

Starting with 2-substituted quinoline-3,4-dicarboxylic acids, a series of substituted 1,2,3,4-tetrahydropyrimido[4,5-c]quinolinone-3-thiones were obtained. The latter compounds were converted to the three novel polyazasteroid series: 1,2,4-Triazolo[3′,4′:2,3]pyrimido[4,5-c]-quinolin-11(12H)ones, imidazo[2′,1′:2,3]pyrimido[4,5c]quinolin-11(12H)ones and 2,3-dihydroimidazo[2′,1′:2,3]pyrimido[4,5-c]quinolin-11(12H)ones. The intermediate 3-hydrazino-1,2-dihydropyrimido[4,5-c]quinolinones and nitrous acid gave the 3-azido derivatives rather than the tetrazolo compounds.     

Synthesis of 4,8-disubstituted 4H,8H-bis[1,2,5]oxadiazolo[3,4–6:3′,4′-e]pyrazines

The dilithio anion of 3,4-N,N′-disubstituted diamino[1,2,5]oxadiazole ( 4a R = benzyl, 4b R = p-methoxybenzyl, 4c R = isopropyl) and cyanogen oxide gave 4,7-disubstituted 5,6-dioximino[1,2,5]oxadiazolo[3,4-b]-pyrazines 5a,b,c. Ring closure to the title compound 1 was accomplished upon heating 5 with sodium hydroxide in ethylene glycol at 150°.     

Direct arylation polymerization toward efficient synthesis of benzo[1,2-c:4,5-c'] dithiophene-4,8-dione based donor-acceptor alternating copolymers for organic optoelectronic applications

Wide-bandgap π-conjugated donor-acceptor (D-A) alternating copolymers consisting of benzo[1,2-c:4,5-c']dithiophene-4,8-dione (BDTD) as the electron-accepting building block have demonstrated outstanding performances in organic bulk heterojunction (BHJ) solar cell devices. But the synthesis of these polymers has been largely limited to conventional polymerization techniques, particularly Stille-coupling based polycondensations, which often involve tedious preactivation of C-H bonds using highly flammable reagents such as butyl lithium and highly toxic reagents such as trialkyl tin chlorides. Herein, we report a “greener” synthetic route of direct arylation polymerization to a series of wide bandgap D-A copolymers with a common acceptor building block of BDTD. The structure–property relationship in these polymers is characterized. We also present the device performances of these polymers in both thin-film field-effect transistors and organic BHJ solar cells involving the BDTD-based polymers as the electron donors and fullerene derivatives as the electron acceptors. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 2554–2564     

2,3-Dihydrospiro[1H-4- and 5-azabenzimidazole-2,1′ -cyclohexane] ( = Spiro[cyclohexane-1,2′(3′H)-1′H-imidazo[4,5-b]pyridine] and Spiro[cyclohexane-1,2′(3′H)-1′H-imidazo[4, 5-c]pyridine]): Reactions with Nucleophiles

The readily available title compounds 4a and 24 react with N-, O-, S-, and C-nucleophiles in presence of MnO₂ to give the corresponding mono- or disubstituted 2H-azabenzimidazoles ( = azaisobenzimidazoles), e.g., 11–18 and 26a–h , respectively, or 2,3-dihydro-1H-azabenzimidazoles ( = dihydro-azabenzimidazoles) such as 9 and 10 and 27 and 28 , respectively, by a 1, 4- or 1,6-Michael addition (Schemes 2 and 4). The bromo-dihydro-1H-azabenzimidazole 4b lost the Br-atom when treated with piperidine or morpholine yielding the corresponding disubstituted 2H-azabenzimidazole 21 (Scheme 3). Reductive ring opening of the substituted spiro compounds leads to mono- and disubstituted diaminopyridines which are intermediates for fused pyridine ring systems with substituents often not available by conventional routes and of potential pharmaceutical interest (see 32 – 37 ). E.g., starting from 4a , a three-step synthesis of the analgesic flupirtine maleate (= ethyl {2-amino-6-[(4-fluorobenzyl)amino]pyridin-3-yl}carbamate maleate = Katadolon®; 39 ) and of its non-fluorinated derivative D-7195 is described. Its analogue 40 was similarly made from the spiro compound 24 .     

Pyrido[2′1′:2,3]imidazo[4,5-c]isoquinoline and the alkylation of pyrido[2′,1′:2,3]imidazo[4,5-c]isoquinolin-5(6H)-one

The reaction of 2-aminopyridine, o-phthaldehydic acid and potassium cyanide gave pyrido[2′,1′:2,3]imidazo[4,5-c]isoquinolin-5(6H)-one, which upon treatment with propargylbromide, yielded both O and N alkylated products. 2-Aminopyridine, o-phthaldehyde and potassium cyanide gave 1-cyano-2-(2-pyridyl)isoindole which rearranged in acid to give the previously unreported parent pyrido[2′,1′:2,3]imidazo[4,5-c]isoquinole. Structures were confirmed using uv, ir, nmr and x-ray spectroscopy.     

Synthesis of 7,8,9,10-tetrahydropyrido[3′,4′:4,5]pyrrolo[2,3-c]quinolines

A series of structurally novel 7,8,9,10-tetrahydropyrido[3′,4′:4,5]pyrrolo[2,3-c,]quinolines, 4a-c , were synthesized via a facile Fischer indole cyclization from the appropriately substituted hydrazinoquinolines 2a-c . Acetamides 4a,c were hydrolyzed to 5a,b and further converted to tertiary amines 6a-c . Potent antihypertensive activity has been observed with a number of the title compounds as well as the intermediate 3a .