New heterocyclic compounds derived from 1,4-dihydro-3(2H)-cinnolinone. Cyclic hydrazides. Note I

The question concerning the synthesis of the 1,4-dihydro-3(2H)cinnolinone was solved and some new tetracyclic derivatives are described. The structure and the synthesis of the two isomers 2-(2-carbomethoxymethylphenyl)phthalazine-1(2H),4(3H)dione and 1-(2-carbomethoxybenzoyl)-1,2-dihydrocinnolin-3(4H)one are discussed.     

Polymers derived from 2,5-diamino-p-benzoquinone-diimide and related compounds

A number of new polymeric materials have been prepared by the self-condensation of 2,5-diamino-p-benzoquinonediimide and by its condensation with 2,5-diamino-p-benzoquinone, 2,5-dihydroxy-p-benzoquinone, and 2,5-dichloro-p-benzoquinone. Ladder polymers were expected, but in every case polymers with some open rings were obtained. 2,5-Diaminohydroquinone was condensed with 2,5-diamino-p-benzoquinonediimide and with 2,5-diamino-p-benzoquinone to produce heat stable polymers but the expected ladder structures were not obtained. Thermogravimetric analyses of the polymers in nitrogen all showed a weight loss at 100–150°C of 3–14% which was presumably due to loss of either chemically combined or absorbed water on the polymer and then only a 5% weight loss up to about 600°C with a final weight loss of 19% at 900°C.     

Thermoanalytical investigations on heterocyclic organic compounds. Part II. Thermal decomposition of substituted 1,4-dihydro-2,4-dioxo-2H-3,1-benzoxazine

The thermal decomposition of substituted 1,4-dihydro-2,4-dioxo-2H-3,1-benzoxazine involves a decarboxylation reaction and the formation of dimeric products that arise by a Diels—Alder reaction involving the ketenimine as diene and dienophile. Significant destabilization of the oxazinedione ring was manifested in the thermal decomposition of 3,4-dihydro-1,3-dioxo-1H-pyrido (3,2-d)(1,3) oxazine (V). The shape of the thermogram is dependent on the experimental conditions. Further decomposition of the dimers leads to dark glassy materials of polymeric nature.     

New heterocycles derived from a simultaneous substitution and reductive acetylation of 2,5-dihydroxy-1,4-benzoquinone by N-containing heterocycles

Reaction of 2,5-dihydroxy-1,4-benzoquinone with pyridine, 3-picoline and acridine in acetic anhydride lead to the preparation of 3-(4-pyridyl)-1,2,4,5-benzenetetrol tetraacetate, 3-[4-(3-methylpyridyl)]-1,2,4,5-benzenetetrol tetraacetate and 3-(9-acridyl)-1,2,4,5-benzenetetrol tetraacetate, respectively. Moreover, it was possible to isolate the complex derived from the corresponding amines and the quinone. The reaction conditions and the ¹H, ¹³C, ir and mass spectra of the new compounds are discussed.     

Synthesis of some heterocyclic compounds derived from indole as antimicrobial agents

Recently, indoles are considered interesting heterocyclic compounds due to their wide range of biological activities such as antimicrobial activity. Herein, some new indole derivatives containing heterocyclic moieties were synthesized using 3-chloro-1H-Indole-2-carbaldehyde (1) as a starting material, then allowed to react with compounds containing active methylene under Knoevenagel condensation and afforded the corresponding compounds (2, 3, 9). Also, the compound (1) when allowed to react with hydrazine derivatives gave the corresponding thiosemiccarbazone, semicarbazone, and hydrazone derivatives (4, 5, 6). Reaction of thiosemicarbazone derivatives with α-halognated carbonyl compounds gave the thiazolyl indole derivatives (10, 12a–b). Cyclic chalcones (11a–c) were obtained when compound (10) reacted with different aromatic aldehydes. The structures of all new synthesized compounds were confirmed on the basis of spectral analysis, IR, 1H NMR, 13C NMR, and MS spectroscopy. All synthesized compounds were evaluated for their antimicrobial activity. Compounds (2, 5, 7, 8, 11a, 12a) showed high antibacterial activity and compounds (3, 6, 9, 10, 11a, 12a) showed high antifungal activity.     

New hypoxia-selective cytotoxines derived from quinoxaline 1,4-dioxides

A new series of quinoxaline 1,4-dioxides, structurally related to the benzotriazine tirapazamine 1 have been prepared starting from 5,6-dichlorobenzofuroxane 2 . The Beirut reaction between 2 and alkyl or aryl thiopropanones afforded the 2-methyl-3-alkyl(aryl)thioquinoxaline 1,4-dioxides 3a-3e . Selective oxidation of 3 with m-chloroperbenzoic acid yielded the sulphinyl 4a-4c and sulphonyl 5a-5b derivatives. Replacement of the sulphonyl group of 5a by chlorine or bromine gave 6 or 7 , while nucleophilic displacement by 3-(N,N-dimethylamino)propylamine afforded 8 . A dimer 9 was prepared from 5a and hydrazine hydrate. The methylthio group of 3a was replaced by using formamidine acetate giving the amino compound 10 . Bromination of the methyl group of 3b afforded 11 , which reacted with 2-aminoethanol giving 12 . Compounds were tested as cytotoxic agents both in oxic and in hypoxic cells.     

Polyesters derived from 1,4-oxathian-2-ones

1,4-Oxathian-2-one ( 1a ) was prepared in high yield by oligomerization of methyl(2-hydroxyethyl)mercaptoacetate ( 3 ) followed by catalytic depolymerization in vacuo. A similar sequence starting with methyl(2-hydroxyethyl)sulfonylacetate ( 5 ) afforded the corresponding sulfone, 1,4-oxathian-2-one-4,4-dioxide ( 1c ), however, 1,4-oxathian-2-one-4-oxide ( 1b ) could not be obtained by this procedure. Ring opening melt polymerization of 1a and 1c afforded low molecular weight crystalline polyesters 2a and 2c . Oxidation of 2a with m-chloroperoxybenzoic acid produced the corresponding polyester 2b containing sulfoxide groups. Thermogravimetric analyses and visual observations indicated 2b to be thermally unstable relative to 2a and 2c .     

Synthesis and properties of polyimides derived from 1,4-bis(4-aminophenoxy)2,5-di-tert-butylbenzene

Novel aromatic polyimides containing symmetric, bulky di-tert-butyl substituents unit were synthesized from 1,4-bis(4-aminophenoxy)2,5-di-tert-butylbenzene (BADTB) and various aromatic tetracarboxylic dianhydrides by the conventional two-stage procedure that included ring-opening polyaddition in a polar solvent such as N,N-dimethylacetamide to give poly(amic acid)s, followed by cyclodehydration to polyimides. The diamine was prepared through the nucleophilic displacement of 2,5-di-tert-butylhydroquinone with p-chloronitrobenzene in the presence of K₂CO₃, followed by catalytic reduction. Depending on the dianhydrides used, the poly(amic acid)s obtained had inherent viscosities of 0.83–1.88 dL g⁻¹. Most of the polyimides formed transparent, flexible, and tough films. Tensile strength and elongation at break of the BADTB-based polyimide films ranged from 68–93 MPa and 7–11%, respectively. The polyimide derived from 4,4′-hexafluoro-isopropylidenebisphathalic anhydride had better solubility than the other polyimides. These polyimides had glass transition temperatures between 242–298°C and 10% mass loss temperatures were recorded in the range of 481–520°C in nitrogen. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1527–1534, 1997     

Highly enantioselective synthesis of rigid, quaternary 1,4-benzodiazepine-2,5-diones derived from proline

[reaction: see text] Proline-derived 1,4-benzodiazepine-2,5-diones are extremely useful scaffolds in medicinal chemistry. In this paper, we describe a protocol for retentive C3 alkylation of these materials, thus accomplishing the direct synthesis of enantiopure quaternary 1,4-benzodiazepine-2,5-diones. The high enantioselectivities (up to 99.5%) are attributed to memory of chirality.     

The reaction between diethyl succinylsuccinate (1,4-diethoxycarbonyl-2,5-dihydroxy-1,4-cyclohexadiene) and amines and its application to polymer synthesis

Polymers having polyamine structures were obtained by the condensation reaction between diethyl succinylsuccinate (1,4-diethoxycarbonyl-2,5-dihydroxy-1,4-cyclohexadiene) and aliphatic diamines. The reactions were carried out in high polar solvents such as N-methylpyrrolidone (NMP) and N,N-dimethylformamide (DMF). The mode of the polymerization reaction and the structure of the polymers were verified by studies of model compounds. The polymers thus obtained were conveniently utilized as coating and adhesive materials and were able to be cast into films.     

2,5-Disubstituted furans from 1,4-alkynediols

1,4-Alkynediols serve as readily available starting materials for isomerisation to 1,4-diketones, which can be converted in situ into the corresponding furans by acid-catalysed dehydration. A range of 2,5-disubstituted furans was prepared using the ruthenium-based catalyst Ru(PPh₃)₃(CO)H₂ with Xantphos at 1 mol % loading.     

Interaction of 2-methyl-2,5-dioxo-1,2-oxaphospholane with trimethylsilyl cyanide

The reaction of 2-methyl-2,5-dioxo-1,2-oxaphospholane (1) with trimethylsilyl cyanide was found to give, depending on conditions, three organophosphorus compounds: trimethylsilyl methyl(2-cyanocarbonylethyl)phosphinate (2), trimethylsilyl methyl(3-trimethylsiloxy-3,3-dicyanopropyl)phosphinate (3) and trimethylsilyl methyl(3-trimethyl-siloxy-3-cyano-2-propenyl)phosphinate (4), On hydrolysis of3 under mild conditions, methyl(3-hydroxy-3,3 dicarboxypropyl)phosphinic acid (7) was obtained. The latter is readily decarboxylated on heating to give methyl(3-hydroxy-3-carboxy-propyl)phosphinic acid (8). The interaction of2 and4 with water or alcohols gives, correspondingly, methyl[2-carboxy(alkoxycarbonyl) ethyl]phosphinic acids (11–13). Methyl(2-oxamoyiethyl)phosphinic acid (14) was prepared by successive treatment of propenylphosphinate4 with HCl gas and water.Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 170–177, January, 1993.     

Azomethine ylides derived from dichlorocarbene and O-acylsalicylaldehyde anils in the synthesis of 2,5-epoxy-2,3,4,5-tetrahydro-1,4-benzoxazepin-2-ones and 2-aminoethanols

Iminiodichloromethanides generated by the reaction of O-acylsalicylaldehyde anils with dichlorocarbene undergo regioselective intramolecular 1,3-dipolar cycloaddition to the ester carbonyl group to give 2,5-epoxy-2,3,4,5-tetrahydro-1,4-benzoxazepin-2-ones. These compounds are expedient precursors for the synthesis of N-(2-hydroxybenzyl)ethanolamines.     

Mixed phosphorous esters derived from diethyl d-tartrate

Summary Mixed methyl, ethyl, propyl, butyl, and allyl esters of the acid ester formed by phosphorous acid with diethyl D-tartrate were synthesized, and some of their properties were studied.     

Structural changes in polymers of diethyl succinylsuccinate(1,4-diethoxycarbonyl-2,5-dihydroxy-1,4-cyclohexadiene) with diamines at high temperatures

The structural changes of the polymers having the following structures: at high temperatures were studied by the spectroscopic and thermal analysis. When the polymers were heated in air, they were oxidized predominantly to polymers having the structure: The rate of oxidation was fast and the reaction was almost completed within 2 hr at 180°C. In the case of polymer 3, an intramolecular cyclization to form acridone was detected as a minor reaction.     

N-Alkoxymethylation of heterocyclic compounds with diethyl phosphite via cleavage of P-O bond

N-Alkoxymethylation of heterocyclic compounds with diethyl phosphite via cleavage of P-O bond was investigated and a series of N3-ethoxymethylated heterocyclic compounds were synthesized. A mechanism in which diethyl phosphite acts as an efficient surrogate of ethanol was proposed and supported by several evidences.