DFT theoretical studies of anions of aniline and its several derivatives

Detailed studies of the molecular and electronic structures, vibrational frequencies, and infrared intensities of [M ⁻] and [M-H ⁻] anions of aniline and its derivatives (2-, 3-, 4-fluoroanilines, N-[(2E)-1-methylbut-2-en-1-yl]aniline, (2-cyclopent-2-en-1-ylphenyl)amine, N-[(2E)-1-methylbut-2-en-1-yl]aniline, and N-cyclopent-2-en-1-ylaniline) have been carried out using the density functional method with UB3LYP functional and 6-31G** basis set augmented with sp diffuse functions on nitrogen, fluorine, and three carbon atoms of benzene ring (in 2, 4, and 6 positions). For comparison, similar calculations were carried out for the closed-shell neutral molecules ([M]). The studies have provided detailed insight into the structure changes that take place in negative ions of aniline and its derivatives.     

Convenient preparative methods for N-aryl-γ-pyridones from γ-pyrones

2-Hydroxymethyl-5-methoxy-4-H-pyran-4-one ( 1 ) reacts with aniline and six aniline derivatives in very dilute aqueous hydrochloric acid at reflux temperature to give the N-aryl-γ-pyridone. A second procedure utilizes the aromatic amine hydrochloride by reacting it with 1 in aqueous medium at reflux temperature. p-Nitroaniline hydrochloride and 1 give the N-aryl-γ-pyridone in 65% yield, as opposed to 12% from the dilute acid procedure.     

A novel synthesis of quinolinium salts via benzotriazole methodology

A novel method for the synthesis of 1,4- and 1,3,4-substituted quinolinium salts and 1,2,4- and 1,2,3,4-substituted-1,2-dibydroquinolines from N-substituted-N(benzotriazol-1-ylmethyl)aniline derivatives is reported.     

Pd catalyzed coupling of 1,2-dibromoarenes and anilines: formation of N,N-diaryl-o-phenylenediamines

1,2-Dibromoarenes were coupled with aniline derivatives to yield N,N-diaryl-o-phenylenediamines in moderate to good yield using a palladium/phosphine or palladium/carbene catalyst system. Under similar conditions, 1,2,4,5-tetrabromobenzene was coupled with aniline derivatives to produce the corresponding tetrasubstituted derivatives which are oxidized on workup to yield azophenines. The sequential reaction of two different anilines with 1-chloro-2-iodobenzene afforded mixed N,N-diaryl-o-phenylenediamines.     

Antimicrobial agents as photostabilizers for rigid poly(vinyl chloride)

Some amide derivatives of ethylene glycol‐bis(2‐aminoethylether)‐N,N,N^′,N^′‐tetraacetic acid (EGTA) have been prepared via their coupling with different aniline derivatives: amino, methyl, chloro, and hydroxy aniline. The EGTA amide derivatives were characterized, and their antimicrobial activities were evaluated. These antimicrobial agents have been investigated as photostabilizers for rigid poly(vinyl chloride) (PVC), suspension PVC, with a K value of 70. Their stabilizing efficiencies were evaluated by determining the percentage of weight loss, the intrinsic viscosities, as well as the amount of formed gel of the photodegraded PVC. The extent of discoloration and the change in the mechanical properties of the photodegraded polymer were also evaluated. The applied materials reduced the loss in weight that resulted from HCl evolution during photodegradation. Both viscosity and gel content measurements showed also a decrease in their values during the degradation process. The decrease in the percentage of gel formation upon applying the investigated photostabilizers reflects the lowering in extent of cross‐linking of the polymer, which implies preserving the mechanical properties of PVC. The extent of discoloration was also improved in the presence of the investigated compounds. The results have proved a greater stabilizing efficiencies of the antimicrobial EGTA amide derivatives than that of the phenyl salicylate ultraviolet (UV) absorber, which is commonly used as an industrial stabilizer. A radical mechanism was proposed to account for the stabilizing action of the investigated products. Copyright © 2011 John Wiley & Sons, Ltd.     

Effective synthesis of <Emphasis Type="Italic">N</Emphasis>-substituted 1,3,5-dithiazinanes by reactions of <Emphasis Type="Italic">N</Emphasis>-methyl-1,3,5-dithiazinane and 1,3,5-trithiane with aromatic amines

A novel procedure has been developed for selective synthesis of N-aryl-1,3,5-dithiazinanes, 1,2,6,7-tetrahydro-3,5,1,7-benzodithiadiazonine, and 6,7-dihydro-1,3,5,7-benzotrithiazonine by reactions of aniline derivatives with N-methyl-1,3,5-dithiazinane or 1,3,5-trithiane in the presence of transition and rare earth metal salts and complexes.     

CHOLESTERYL DELTA-AMINOBUTYL SULFIDES FROM CYCLIC SULFONIUM SALTS

Abstract

In the course of studies with cholesterol sulfur derivatives, cholesteryl 3β-sulfonium salts were observed to act as alkylating agents toward amines.¹ 3β-Dimethyl-sulfonio-5-cholestene salts and aniline gave N-methyl-aniline, and not N-cholesterylaniline. Thus, the reaction seemed to be controlled more by steric requirements than by stabilizing factors involved in incipient formation of the homoallylic carbonium ion.     

On the formation of homo-aza-steroids and derivatives by beckmann rearrangement. Antitumor activity of stereoisomers homo-aza-steroidal esters

The Beckmann rearrangement of steroidal oximes is reported. Different methods of esterification of homo-aza-steroids with carboxylic derivatives of N,N-bis(2-chloroethyl)aniline are reported. The lipophilic nature of the steroidal hormones is the reason for searching compounds containing as the biological platform the steroid molecule and as the active moiety the alkylating agent, such as nitrogen mustards linked to the steroid with a stable bond or with an easily cleaved ester or ether molecule and different other active species, hopefully to transport and deliver the alkylating agent to the specific target tissue. The concept to design hybrid compounds containing as the biological platform steroidal lactams and as the alkylating congener carboxylic derivatives of N,N-bis(2-chloroethyl)aniline might form compounds with synergistic activity. The findings suggest that the conformation of the alkylating agent influences the anticancer activity, while the amide group of the lactam molecule is important for activity in L1210 leukemia. These hybrid compounds with a modified steroid as the biological platform furnish derivatives with advantages compared to the unmodified steroids with alkylating agents. Different methods of esterification of homo-aza-steroids with carboxylic derivatives of N,N-bis(2-chloro-ethyl)aniline are reported.     

Synthesis and Acylation of peri-Amino Derivatives of Anthra[1,9-cd]pyrazol-6-one

Heating of 5- and 7-chloro-6H-anthra[1,9-cd]pyrazol-6-ones in butylamine and aniline gives the corresponding peri-amino-substituted anthrapyrazole derivatives. Acylation of the latter occurs at the N¹ atom of the heterocyclic fragment to afford monoacyl derivatives having an ana-quinonimine structure.     

N-Heterocyclization of Primary Amines with Dihalides Using Microreactors

A practical, rapid, and efficient reaction using microreactors for the direct N-alkylation from aniline derivatives and alkyl dihalides has been achieved in the presence of aqueous potassium carbonate at an elevated temperature. This improved synthetic methodology provides a straightforward microfluid approach to the synthesis of a variety of N-aryl azacycloalkanes.     

Synthesis of (1′S*,2R*,3R*)- and (1′S*,2R*,3S*)-N-arylsulfonyl-2-(1′-halogenethyl)-3-methylindolines and their selective toxicity against SH-SY5Y cell line

N-tosyl-2- and N-tosyl-4-halogen-substituted derivatives of 2-(1-methylbut-2-en-1-yl)aniline were synthesized and their molecular iodine-mediated cyclization was investigated. The cyclization upon interaction of N-tosyl-6-methyl-2-(1-methylbut-2-en-1-yl)aniline with molecular iodine in methyl tert-butyl ether or acetonitrile was studied, as well as the interaction of this sulfonamide with N-bromosucinimide in dichloromethane. Synthesized (2R*,3R*)- and (2R*,3S*)-N-arylsulfonyl-2-(1-halogenoethyl)-3-methylindoline derivatives showed cytotoxic activity against HEK293 cells, SH-SY5Y, Jurkat, and HepG2 cell lines. The compounds (2R*,3S*)-N-arylsulfonyl-7-bromo-2-(1-halogenoethyl)-3-methylindoline cis- 4a , stereoisomeric (2R*,3R*)-trans- 4h and (2R*,3S*)-N-tosyl-7-chloro-2-(1-halogenoethyl)-3-methylindoline cis- 4h demonstrated selective toxicity against SH-SY5Y cell line (IC₅₀ ≈ 3 ÷ 5 μM), and did not affect HEK293, Jurkat, and HepG2 cells.     

N‐Glycosyl‐N′‐[p‐(isoamyloxy)phenyl]‐thiourea Derivatives: Potential Anti‐TB Therapeutic Agents

Thiocarlide (THC; N,N′‐bis[p‐(isoamyloxy)phenyl]‐thiourea; also known as Isoxyl^®) has been used in the past as an anti‐tuberculosis agent. In an effort to improve the therapeutic value of THC, several N‐glycosyl‐N′‐[p‐(isoamyloxy)phenyl]‐thiourea derivatives were synthesized by coupling an aniline derivative and glycosyl isothiocyanates. The minimum inhibitory concentration (MIC) values of the new products against M. tuberculosis were determined.     

Synthesis of methyl derivatives of 8-desmethylxanthyletine and 8-desmethylseseline,potential antiproliferative agents

A number of new methyl derivatives of pyranocoumarins, related to 8-desmethylxanthyletine and to 8-desmethylseseline, were synthesized. The syntheses were performed by cyclization in boiling N,N-diethyl aniline of the propargyl or methylpropargyl ethers of the appropriate methyl derivatives of 7-hydroxycou-marin. Methyl groups have been introduced into positions which look most promising for enhancement of the photoreactivity of the compounds towards DNA.     

Formation of Stable Rhodium η6‐Arene Complexes with Aniline Derivatives

Three new, hitherto unknown, rhodium complexes with aniline and two of its derivatives (2, 6‐dimethylaniline and N‐methylaniline) are presented. All complexes have been characterized by X‐ray analysis.     

Synthesis of 2-(furazanyl)indolizines

Heating ofN-[2-(4-methylfurazan-3-yl)-2-oxoethyl]-2-methylpyridinium bromides inN,N-dimethylaniline affords indolizine derivatives, whereas in aniline a mixture of indole and indolizine derivatives is formed. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp.2375–2376, December, 1999.     

Synthesis of 4,5,6,7‐Tetrabromo‐1H‐benzimidazole Derivatives

A convenient and simple method for the preparation of polybrominated benzimidazole derivatives has been described. Reaction of 4,5,6,7‐tetrabromo‐1‐(3‐chloropropyl)‐1H‐benzimidazole, obtained by alkylation of 4,5,6,7‐tetrabromo‐1H‐benzimidazole (TBBi) with 1‐bromo‐3‐chloropropane in the presence of KOH, with morpholine, aniline, benzylamine, N‐methyl piperazine, and 2‐arylpyrrolidines afforded new TBBi derivatives.     

Oxidative arylamination of 1,7-dihydroxynaphthalene

1,7-Dihydroxynaphthalene reacts with aniline orp-toluidine in the presence of oxidants to give the correspondingN-aryl-7-hydroxy-1,4-naphthoquinone 4-imines, 2-arylamino- and 2,8-diarylamino-N-aryl-7-hydroxy-1,4-naphthoquinone 4-imines, and benzo[a]oxophenoxazinimine derivatives. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 347–350, February, 1999.     

Efficient and Regioselective Bromination of Aromatic Compounds with Ethylenebis(N-methylimidazolium) Ditribromide (EBMIDTB)

A regioselective and highly efficient method for bromination of phenol and aniline derivatives using ethylenebis(N-methylimidazolium) ditribromide (EBMIDTB) as an efficient reagent in dichloromethane at ambient temperature is reported. The reagent can be recovered and reused several times.     

超声法合成新型3-(5-氯/苯氧基-3-甲基-1-苯基-4-吡唑基)异噁唑N-取代苯基去甲去氢斑蝥酰亚胺衍生物

去甲去氢斑蝥素与取代芳胺反应得到了一系列N-取代苯基去甲去氢斑蝥酰亚胺, 再与5-氯/苯氧基-4-(α-氯-α-肟基甲基)-3-甲基-1-苯基吡唑甲酰基氯代肟发生1,3-偶极环加成反应生成一系列未见报道的3-(5-氯/苯氧基-3-甲基-1-苯基-4-吡唑基)异噁唑N-取代苯基去甲去氢斑蝥酰亚胺衍生物. 所合成化合物经元素分析, IR, ¹H NMR, ¹H-¹HCOSY, NOESY确证结构.     

Nitrogen bridgehead compounds. Part 50 . Vilsmeier-haack acylation of 6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-ones,Part 5

6-Methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-ones 1-5 were subjected to Vilsmeier-Haack acylation with complexes of phosphoryl chloride and different amides. Acylation at position 9 of the pyridopyrim-idines was successful with the iminium salt formed in situ from N-formylpiperidine, N-methylformanilide or N,N-diethylbenzamide, but unsuccessful with the iminium salt formed from N,N-diethylacetamide or N,N-di-ethylisobutyramide, respectively. The iminium salt formed from formanilide, N-methylpyrrolidinone or formamide reacted only with those tetrahydropyridopyrimidinones which contain a strongly electronegative substituent (e.g. CN or CO₂Et) in position 3. With the latter derivatives, the 9-phenylaminomethylene group could be introduced using N,N-diphenylformamide or in a “one-pot” procedure with aniline and triethyl orthoformate. Ethanolysis of 9-N-methyl-N-phenylaminomethylene derivatives 15 and 19 afforded 9-ethoxy-methylene compounds 26 and 27 in the presence of hydrogen chloride. The structures of the 9-substituted 6-methyltetrahydropyridopyrimidin-4-ones 14-25 were elucidated by means of uv, ¹H and ¹³C nmr spectroscopy. 9-Piperidinomethylene 14 , 9-(N-methyl-N-phenylaminomethylene 15-19 and 9-(N-methyl-2-pyrrolidinylidene) 21 derivatives exist as E geometric isomers. 9-Phenylaminomethylene-6-methyl-4-oxo-6,7,8,9-tetra-hydro-4H-pyrido[1,2-a]pyrimidine-3-carbonitrile 20 displays a solvent-dependent E-Z isomerism. The bis-compound 25 contains both E and Z geometric exo C ? CH double bonds. 9-Benzoyl derivatives 23 and 24 exist predominantly as the 1,6,7,8-tetrahydropyridopyrimidin-4-one tautomer.