O,N-Dimethylation of 5,6-dihydroxynicotinic acid

AnO,N-dialkylation product, 1-methyl-5-metlioxy-6-oxo-1,6-diliydropyridine-3 carboxylic acid, is formed in the reaction of 5,6-dihydroxynicotinic acid with dimethylsulfate.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1554–1555, June, 1996.     

Synthesis and structure of the unsymmetrical β-diimine precursor: The β-iminoamine

The reaction of benzoylacetone with ortho-substituted aniline derivatives gives the unsymmetrical β-iminoamine ligands (5–8) with high yields. A convenient synthesis is described. These compounds have been characterized by NMR and IR spectroscopies. The structure of the β-iminoamine 5, 3-N-(2,6-diisopropylphenylamino)-1-phenyl-1N-(2,6-diisopropylphenylimino)but-2-ene, was solved by X-ray diffraction methods.     

Reaction of 3-Carene with Some Nitrating Agents

From the reaction products obtained by treating 3-carene with dinitrogen tetroxide a crystalline compound N-[(1R,6R)-3-methyl-6-(1-methyl-1-nitroxyethyl)cyclohex-3-enyl]-N'-{1S,6S)-4- methyl-6(1- methyl-1-nitroxyethyl)cyclo-hex-3-enyl]-E-diazene-N,N'-dioxide was isolated. Mainly nitrate of -terpineol formed in reaction of 3-carene with 70% nitric acid.     

Synthesis of 3H-thieno[3,2-c]-1,2-dithiole-3-thione and its reaction with n-butylamine

A convenient synthesis of 3H-thieno[3,2-c]-1,2-dithiole-3-thione (7) is proposed. The reaction of 7 with n-butylamine afforded the N-butylthieno[3,2-c]isothiazole-3(2H)-thione (7a) in dynamically equilibrium [1] with its 3H-thieno[3,2-c]-1,2-dithiole-N-butyl-3-imino isomer 7b. Characterizations and antimicrobial activities of the synthesized products are reported.     

Reaction of γ-picoline N-oxide with ketenimines in the presence of organic acids: Preparation of α-acyloxyamides

A synthesis of a-acyloxyamides is described which utilizes the reaction of 7-picoline N-oxide and various organic acids with diphenylketene N-p-tolylimine.     

1,2-fused pyrimidines. V. Synthesis of 1-alkyl or phenyl-2H-dipyrido-[1,2-a:2′,3′-d]pyrimidine-2,5(1H)-diones

The reaction of 2-[(N-acyl, N-alkyl or phenyl)amino]-4H-pyrido[1,2-a]pyrimidin-4-ones 8a-g with the N,N-dimethylformamide/phosphorus oxychloride Vilsmeier reagent 1 (95°, 90 minutes) afforded 1-alkyl or phenyl-2H-dipyrido[1,2-a:2′,3′-d]pyrimidine-2,5(1H)^?diones, 3-alkyl substituted or not, 10a-g . The starting compounds 8 were prepared by treating 2-amino-4H-pyrido[1,2-a]pyrimidin-4-ones N-alkyl substituted 7a,b or N-phenyl substituted 4 with excess anhydrides (130°, 7 hours) when the 2-(alkylamino) derivatives 7 were used in the reaction, compounds 8 were obtained along with very small amounts of 3-acyl-2-(alkylamino)-4H-pyrido[1,2-a]pyrimidin-4-ones 9 .     

Synthesis of some new 3-pyrazolyl-substituted-4(3H)quinazolinones

N-(1-Phenyl-3-methylpyrazol-5-yl)-o-aminobenzamide reacted with orthoesters to yield some new 3-pyrazolyl-substituted-4(3H)quinazolinones (VIIa,b,c,d). An alternative synthesis of Vllb was accomplished by reaction of acetylanthranyl with l-phenyl-3-methyl-5-aminopyrazole.     

4-Methylumbelliferyl 5-Acetamido-3,4,5-trideoxy-α-D-manno-2-nonulopyranosidonic Acid: Synthesis and Resistance to Bacterial Sialidases

The synthesis of 4-methylumbelliferyl α-D -glycoside 13 of N-acetyl-4-deoxyneuraminic acid and its behaviour towards bacterial sialidases is described. N-Acetyl-4-deoxyneuraminic acid ( 1 ) was transformed into its methyl ester 2 and then acetylated to give the anomeric pentaacetates 3 and 4 of methyl 4-deoxyneuraminate and the enolacetate 5 (Scheme). A mixture 3/4 was treated with HCl/AcCl to give the glycosyl chloride, which was directly converted into the 4-methylumbelliferyl α-D -glycoside 9 of methyl 7-O,8-O,9-O,N-tetraacetylneuraminate and into the 2,3-dehydrosialic acid 11 . The ketoside 9 was de-O-acetylated to 12 with NaOMe in MeOH. Saponification (NaOH) of the methyl ester 12 followed by acidification gave the free 13 , which was also converted into the sodium salt 14 by passage through Dowex 50 (Na⁺). The 4-deoxy α-D -glycoside 13 is not hydrolyzed at significant rates by Vibrio cholerae and Arthrobacter ureafaciens sialidase. Neither the free N-acetyl-4-deoxyneuraminic acid ( 1 ), nor the α-D -glycoside 13 inhibit the activity of these sialidases.     

Allgemeiner Zugang zu Polyaminen mit Ethan-1,2-diamin-Einheiten: Synthese von nicht natürlich vorkommenden homologen und isomeren N1,4-Di(4-cumaroyl)sperminen

█tl="American"█The synthesis of the three N,N′-di(4-coumaroyl)tetramines, i.e., of (E,E)-N-{3-[(2-aminoethyl)amino]propyl}-3,3′-bis(4-hydroxyphenyl)-N,N′-(ethane-1,2-diyl)bis[prop-2-enamide] ( 1a ), (E,E)-N-{4-[(2-aminoethyl)amino]butyl}-3,3′-bis(4-hydroxyphenyl)-N,N′-(ethane-1,2-diyl)bis[prop-2-enamide] ( 1b ), and (E,E)-N-{6-[(2-aminoethyl)amino]hexyl}-3,3′-bis(4-hydroxyphenyl)-N,N′-(ethane-1,2-diyl)bis[prop-2-enamide] ( 1c ), is described. It proceeds through stepwise construction of the symmetric polyamine backbone including protection and deprotection steps of the amino functions. Their behavior on TLC in comparison with that of 1,4-di(4-coumaroyl)spermine (=(E,E)-N-{4-[(3-aminopropyl)amino]butyl}-3,3′-bis(4-hydroxyphenyl)-N,N′-(propane-1,3-diyl)bis[prop-2-enamide]; 2 ) is discussed.     

Synthesis of (3S,3S′,4S,4S′)-1,1′-ethylenedipyrrolidine-3,3′,4,4′-tetraol and related diamino diols: donor–acceptor hydrogen-bonding motifs of the C2 symmetric 3,4-dihydroxypyrrolidine unit

Enantiopure 1,1′-ethylenedipyrrolidines possessing 3,4-disubstitution have been prepared from esters of l-(+)-tartaric acid. Although diacylation routes via the diacetoxypyrrolidin-2,5-diones were problematic, N,N-dialkylation protocols proved to be reliable and led to the synthesis of (3S,3S′,4S,4S′)-1,1′-ethylenedipyrrolidine-3,3′,4,4′-tetraol, (3R,3′S,4R,4′S)-3,4-diamino-1,1′-ethylenedipyrrolidine-3′,4′-diol and (3R,3′R,4S,4′S)-3,3′-diamino-1,1′-ethylenedipyrrolidine-4,4′-diol. The tetraol possesses a crystal structure that exhibits an unusual zig-zag intermolecular pattern comprising a network of hydrogen bonds involving the terminal hydroxyl groups and a nitrogen atom of one of the pyrrolidine rings.     

3-Bromo-propenyl acetate in organic synthesis: an expeditious route to 3-alkyl-4-acetoxy-5-iodomethyl isoxazolidines

N-Trimethylsilyloxy-N-benzyl-1-alkyl-2-acetoxy-3-buten-1-amines 13, obtained in good yields and moderate diastereoselectivities by TMSOTf promoted α-acetoxyallylation of nitrones using metallic zinc and 3-bromo-propenyl acetate 11, are exploited in a stereospecific 5-exo-trig iodocyclization reaction to afford 4,5-cis-3-alkyl-4-acetoxy-5-iodomethyl isoxazolidines 14, promising starting materials for the synthesis of pyrrolidine azasugars.     

Highly efficient synthesis of chromeno[2,3-b]pyridine using Graphene-Oxide/N1,N3-bis (pyridin-2-ylmethyl)propane-1,3-diamine-Copper nanocomposites as a novel catalyst

Recent studies about innovations in GO/N-Ligand-Cu Nano-Composites have been done. Graphene-Oxide is improved with N¹,N³-bis (pyridin-2-ylmethyl)propane-1,3-diamine and after that is matched with copper (Cu). The chemical composition and the structure of the catalyst were analyzed by TGA/DTG, EDX, XRD, FT-IR, TEM, and SEM. The results demonstrated that GO/N-Ligand-Cu was able to catalyze the chromeno[2,3-b]pyridine compounds to obtain high yields in short reaction time. The results of the present work are hoped to assist the growth of a new class of heterogeneous catalysts as the high-function candidate for industrial applications.     

2-[3-(Trifluoromethyl)phenyl]furo[3,2-b]pyrroles: synthesis and reactions

The synthesis and reactions of methyl 2-[3-(trifluoromethyl)phenyl]-4H-furo[3,2-b]pyrrole-5-carboxylate (1a) are described. Upon reaction with methyl iodide, benzyl chloride, or acetic anhydride, this compound gave N-substituted products 1b-d. By hydrolysis of compounds 1a-c, the corresponding acids 2a-c were formed, or by reaction with hydrazine-hydrate, the corresponding carbohydrazides 3a-c were formed. By heating 2-[3-(trifluoromethyl)phenly]-4H-furo[3,2-b]pyrrole-5-carboxylic acid (2a) in acetic anhydride, 4-acetyl-2-[3-(trifluoromethyl)phenyl]furo[3,2-b]pyrrole (4) was formed. By hydrolysis of 4, 2-[3-(trifluoromethyl)phenyl]-4H-furo[3,2-b]pyrrole (5a) was formed, and reactions with methyl iodide or benzyl chloride gave N-substituted products 5b-c. The reaction of 4 with dimethyl butynedioate gave substituted benzo[b]furan 6. Compound 3a reacted with triethyl orthoesters giving 7a-c, which afforded with phosphorus (V) sulphide the corresponding thiones 8a-c. The thiones 8a-c reacted with hydrazine hydrate to form hydrazine derivatives 9a-c. The reaction of triethyl orthoformiate with compounds 9a-c led to furo[2′,3′: 4,5]pyrrolo[1,2-d][1,2,4]triazolo[3,4-f][1,2,4]triazines 10a-c. Hydrazones 11a-c were formed from 3a-c and 5-[3-(trifluoromethyl)phenyl]furan-2-carboxaldehyde. The effect of microwave irradiation on some condensation reactions was compared with “classical” conditions. The results showed that microwave irradiation shortens the reaction time while affording comparable yields.     

A formal method for the de-N,N-dialkylation of Sommelet–Hauser rearrangement products

Selective amine de-alkylation enables the conversion of Sommelet–Hauser rearrangement products into 2-aryl-2-bromoacetic acid derivatives. These compounds are valuable synthetic intermediates in the synthesis of α-aryl-α-amino or α-aryl-β-amino acid derivatives. The method presented herein is a formal de-N,N-dialkylation of Sommelet–Hauser rearrangement products.     

Synthesis of (3RS)- and (3SR)-acetoxy-(3aRS,8bSR)-N-acetyl-5-methoxy-1,2,3,3a,4,8b-hexahydrocyclopenta[b]indoles

Stereoisomeric 3-acetoxy-5-methoxy-1,2,3,3a,4,8b-hexahydrocyclopenta[b]indoles differing by the configuration of the C³ atom were synthesized. The reaction of N-acetyl-6-(cyclopent-2-en-1-yl)-2-methoxyaniline with 50% hydrogen peroxide in the presence of Na₂WO₄-H₃PO₄ in AcOH gave (3RS,3aRS,8bSR)-N-acetyl-3-hydroxy-5-methoxy-1,2,3,3a,4,8b-hexahydrocyclopenta[b]indole which was converted into the corresponding 3-O-acetyl derivative by treatment with acetic anhydride in pyridine. N-Acetyl-6-(cyclopent-2-en-1-yl)-2-methoxyaniline reacted with iodine in methylene chloride in the presence of NaHCO₃ to produce (3SR,3aRS,8bSR)-3-acetoxy-5-methoxy-1,2,3,3a,4,8b-hexahydrocyclopenta[b]indole which was subjected to acetylation at the nitrogen atom by reaction with acetic anhydride. The structure of (3RS,3aRS,8bSR)-N-acetyl-3-hydroxy-5-methyl-1,2,3,3a,4,8b-hexahydrocyclopenta[b]indole was proved by X-ray analysis. Original Russian Text ? N.A. Likhacheva, A.A. Korlyukov, R.R. Gataullin, 2009, published in Zhurnal Organicheskoi Khimii, 2009, Vol. 45, No. 3, pp. 406–409.     

3-Deazaguanine N7- and N9-(2′-Deoxy-β-D-ribofuranosides): Building Blocks for Solid-Phase Synthesis and Incorporation into Oligodeoxyribonucleotides

Oligonucleotides continuing 3-deaza-2′-deoxyguanosine ( I ) or its N⁷-regioisomer 2 were prepared by solid-phase synthesis using P¹¹¹ chemistry. Protection of ¹ or ² with N,N V-dimethylformamide diethyl acetal followed by 4,4′-dimethoxytritylation afforded imidazo[4,5-c]pyridines 10b and 11b , respectively. The latter were converted into the 3′-phosphonates 10c or lie, respectively; the cyanoethyl N,N-diisopropylphosphoramidite 10d was also prepared. The oligonucleotide building blocks were employed in automated solid-phase synthesis. 1 he self-complementary oligomers 13 , 15 , and 17 were prepared and characterized by enzymatic hydrolysis with snake-venom phosphodiesterase followed by alkaline phosphatase. There CD spectra exhibited the general structure of a B-DNA.     

Palladium-catalyzed dual C–H activation of N-phenyl-1H-indole-3-carboxamides for the synthesis of 5,11-dihydro-6H-indolo[3,2-c]quinolin-6-ones

In this paper, we report a palladium-catalyzed dual C–H activation of N-phenyl-1H-indole-3-carboxamides for the synthesis of 5,11-dihydro-6H-indolo[3,2-c]quinolin-6-ones. The optimal reaction conditions were to use 20 mol % of Pd(TFA)₂ as the catalyst, 2.0 equivalents of Cu(OAc)₂ as the oxidant, 1.0 equivalent of K₃PO₄ as the base, and 3.0 equivalents of PivOH as the additive in DMF/dioxane (1: 9). When carried out at 120 °C for 24 h, the reaction could provide nineteen target indoloquinolinones in modest to excellent yields, including the N,N′-dimethylated and N,N′-unsubstituted products which are inaccessible by the reported C–H activation methodologies. The dual C–H activation reaction was also applicable to N-phenyl-1H-indole-2-carboxamides and formed the corresponding 5,7-dihydro-6H-indolo[2,3-c]quinolin-6-ones. A plausible reaction mechanism based on the data from the control experiments and the literatures was proposed to account for the transformation.     

Highly stereoselective aziridine ring-opening with phenylselenide anion and selective intramolecular aldol closure for the enantiopure synthesis of γ-aminocyclopentene derivatives

A practical and enantiopure synthesis for the preparation of key intermediates of conformationally locked γ-amino acid and nucleoside analogues is described. First, a highly stereoselective aziridine ring-opening reaction with phenylselenide anion was employed for the stereoselective synthesis of the chiral aminoselenide (1S,2S,1′S)-8, which after N-benzylation was transformed into the corresponding allyl amine (1S,1′S)-7 by oxidation with H₂O₂. Then, dihydroxylation–dehomologation of (1S,1′S)-7 with (OsO₄/NMO, NaIO₄) selectively afforded the desired γ-aminocyclopentene aldehyde (S)-1 and its corresponding γ-amino acid (S)-2 via an intramolecular selective aldol-condensation catalyzed by an internal base.     

Synthesis of derivatives of 3-acetyl-2-aminopyrrole and pyrolo[2,3-d]pyrimidine from monoacetylketene aminals

A new scheme for the synthesis of pyrrolo[2,3-d]pyrimidines from monoacetylketene animals was proposed. Reactions of monoacetylketeneN-benzoyl- andN-acetylaminals with -bromoacetophenone afforded the corresponding 3-acetyl-2-acylamino-5-phenyl- lH-pyr-roles, which underwent cyclization to 2,4,6-trisubstituted 7Hl-pyrrolo[2,3-d]pyrimidines under the action of ammonium acetate in boiling BuOH.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp, 1808–1811, July, 19W