Synthesis and Reactions of Some New 6,7-Dihaloquinolones Bearing Mercapto Groups

Reaction of the 6-chloro-7-fluoroquinoline 7 with methyl 2-mercaptoacetate, methyl 3-mercaptopropionate, or sodium thiophenolate furnished the quinolone derivatives of 3-carbonylsulfanyl-acetic acid methyl ester 8, the propionoate analogue 10, and 3-carbothioic acid S-phenyl ester 11 respectively. Ester 8 was converted into the 3-carbothioic acid S-carbamoyl derivative 9. Analogously, treatment of the 6,7-diflouroquinolone 12 with amino or mercapto precursors led to the formation of 13 and 14 respectively. Reaction of 14 with aqueous NH₃ or H₂O₂/AcOH afforded the acetamide 15 and the sulfoxide 16 analogues, respectively. The 5′-thioalkyl-acyclic quinolone nucleosides 19 and 20 were obtained from reaction of the mesylate derivative 18, prepared from the free nucleoside 17, with the methanthiolate and thiophenolate anions.     

Über kondensierte Heterocyclen aus β-Isothiocyanatoketonen und Aminoalkoholen bzw. Diaminen

2- and 3-aminoalcohols, o-aminobenzylalcohol, o-hydroxybenzylamine and o-amino(thio)-phenol react with 4-isothiocyanato-4-methyl-2-pentanone (1) to yield derivatives of condensed heterocycles (oxazolopyrimidines7, pyrimidooxazine8, pyrimidobenzoxazines9, 10, pyrimidobenzoxazole11 a and pyrimidobenzothiazole11 c respectively). Ethylenediamine or 1,3-diaminopropane react with1 to yield either imidazo-pyrimidine13 and pyrimidopyrimidine14 respectively or the 1,2-ethylene- and trimethylenebisdihydro-2(1H)-pyrimidinethione15 a, b respectively, according to the molar ratio of the reactants. o-Phenylenediamine gives pyrimidobenzimidazole11 d. 11a undergoes ring cleavage in boiling dimethylformamide followed by methylpyrimidine-pyridine rearrangement to dihydrohydroxyphenylamino-2(1H)-pyridinethione12, while15 a is converted into the bis-4-(ethanediimino)-pyridinthione16.     

Synthetic Access to New Pyridone Derivatives through the Alkylation Reactions of Hydroxypyridines with Epoxides

General methods for the preparation of a variety of pyridone and oxypyridine derivatives are described. 2‐,3‐,4‐Hydroxy pyridine and 2‐pyridinemethanol were alkylated with ethylene‐, propylene‐, and stryrene‐oxide and epichlorohydrin in the presence of different Lewis acids as a catalyst. The best yield of 3a was achieved in the presence of CdI₂/BF₃ · OEt₂. The corresponding pyridone derivatives (3a–d, 7a–d) were obtained from the reaction of 2‐and 4‐hydroxypyridine with oxiranes in good yields, whereas oxypyridine derivatives (5a–d, 9a,b) were obtained from reactions of 3‐hydroxypyridine and 2‐pyridinemethanol with oxiranes. Chlorohydrines (3d, 5d, 7d) were easily converted to corresponding epoxy derivatives (10, 11, 12) in basic medium; then amino alcohols (13–17) were obtained from the reaction of these epoxy derivatives with amines.     

Über die Darstellung von substituierten 3,4-Dihydro-2(1H)-pyrimidin-iminen und 2-Aminopyrimidinen aus Guanidin und α,β-ungesättigten Ketonen

Guanidine reacts with the 2-alken-1-ones4 a-f and5 to give the unstable dihydropyrimidinimines (or-amines respectively)8 a-f (I, II or III respectively) and the hexahydroquinazolinimine (-amine)9 (I, II or III);8 a-f lose H₂, partly in the course of the reaction, partly during recrystallization to yield the 2-pyrimidinamines10 a-c, e, f, and the 4-methyl-5,6,7,8-tetrahydro-2-quinazolinamine11. With picric acid the unstable compounds8 d, f and9, resp. are converted into the stable 2-amino-3,4-dihydro-1H-2-pyrimidinylium picrates12 d and into the 2-amino-4-methyl-3,5,6,7,8,8 a-hexahydro-1H-2-quinazolinium picrate (13 resp.14, 15)¹⁸, whereas8 e reacts with HCl to give the chloride12 e. The structures of12 d-f follow from their NMR-spectra, and of10 a-c, e, f and11 by alternative syntheses by known methods^12–17 (e.g. from -diketones and guanidine). The reaction of8 d-f and9 to10 d-f and11 respectively is compared with previously described dehydrogenation and disproportionation reactions, especially of 3,4-dihydro-2(1H)-pyrimidinones (6 d ⁴,23 ²⁰) and-thiones (30 ¹) of similar structure and formulated as a base-catalysed elimination of H₂.

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HerrnA. Fuchsgruber danken wir für die Aufnahme und Hilfe bei der Interpretation der NMR-Spektren.     

Synthetic Studies on Sialoglycoconjugates 44: Synthesis of KDN-Gangliosides Gm4 and GM3

Abstract

Ganglioside GM₄ and GM₃ analogs, containing 3-deoxy-D-glycero-D-galacto-2-nonulopyranosonic acid (KDN) in place of N-acetylneuraminic acid, have been synthesized. KDN, prepared by the condensation of oxalacetic acid with D-mannose, was converted into methyl (phenyl 4,5,7,8,9-penta-O-acetyl-3-deoxy-2-thio-D-glycero-D-galacto-2-nonulopyranosid)onate (2) via methyl esterification, O-acetylation and replacement of the anomeric acetoxy group with phenyl thio. Glycosylation of 2 with 2-(trimethylsilyl)ethyl 6-O-benzoyl-β-D-galactopyranoside (3) or 2-(trimethylsilyl)ethyl O-(6-O-benzoyl-β-D-galactopyranosyl)-(1→4)-2,6-di-O-benzoyl-β-D-glucopyranoside (4) was performed, using N-iodosuccinimide-trimethylsilyl trifluoromethanesulfonate as the glycosyl promoter, to give 2-(trimethylsilyl)ethyl O-(methyl 4,5,7,8,9-penta-O-acetyl-3-deoxy-D-glycero-α-D-galacto-2-nonulopyranosylonate)-(2→3)-6-O-benzoyl-β-D-galacto-pyranoside (5) and 2-(trimethylsilyl)ethyl O-(methyl 4,5,7,8,9-penta-O-acetyl-3-deoxy-D-glycero-α-D-galacto-2-nonulopyranosylonate)-(2→3)-(6-O-benzoyl-β-D-galactopyrano-syl)-(l→4)-(2,6-di-O-benzoyl-β-D-glucopyranoside (9), respectively. Compounds 5 and 9 were converted via O-acetylation, selective removal of the 2-(trimethylsilyl)ethyl group and subsequent imidate formation, into the corresponding trichloroacetimidates 8 and 12, respectively. Glycosylation of (2S,3R,4E)-2-azido-3-O-benzoyl-4-octadecene-l,3-diol (13) with 8 and 12 in the presence of boron trifluoride etherate afforded the expected β-glycosides 14 and 17, which were transformed via selective reduction of the azido group, coupling with octadecanoic acid, O-deacylation and de-esterification, into the target gangliosides 16 and 19 in high yields.     

SYNTHESIS OF NEW 3-SUBSTITUTED AND SPIRO 1,5-BENZODIAZEPIN-2-ONES UNDER PHASE-TRANSFER CATALYSIS CONDITIONS

1,3-Dihydro-4-phenyl-1,5-benzodiazepin-2-one 1 was treated with bromine in 1:1 molar ratio to get the corresponding 3-bromo derivative 2 which in turn reacted with different nucleophiles to get the corresponding 3-substituted derivatives 3–11. The cyclized compounds 4_a , 5_a , 7_a,b , and 9_a–c were achieved on refluxing compounds 4, 5, 6_a,b , or 8 _a–c respectively in diphenyl ether. Compound 1 was benzoylated with benzoyl chloride to give the corresponding 1-benzoyl derivative 12 which reacted with bromine in 1:2 molar ratio to yield the corresponding 3,3-dibromo derivative 13. Spiro benzodiazepines 14_a–d–16 were obtained by reacting compound 13 with the proper bidentates. Compound 1 was treated with formaldehyde and secondary amines or thiols to give Mannich bases or sulphides 17–21, respectively.     

Kondensierte Heterocyclen aus β-Isothiocyanatoketonen und Aminocarbonsäuren

On reaction of glycine, anthranilic acid and anthranilamide respectively with 4-isothiocyanato-4-methyl-2-pentanone (1), derivatives of condensed heterocycles (oxazolopyrimidine5, pyrimidobenzoxazine7 a, pyrimidobenzodiazine7 c) are formed. The same holds for the reaction of dithiocarbamates, prepared from glycine and CS₂ in aqueous NaOH, with 4-methyl-3-penten-2-one and cinnamaldehyde respectively (12 a, b). The reaction of hot dimethylformamide with7 a leads under initial aminolysis to pyrimidine-anthranildimethylamide2 i; this is subsequently transformed partly through methylpyrimidine-pyridine rearrangement into the N-4-pyridine-anthranil-N,N-dimethylamide10 d, partly under further aminolysis byDMF followed by rearrangement to the dimethylaminodihydro-2(1H)-pyridinethione10 c. 5 is converted to dihydro-4-methylamino-2(1H)-pyridinethione (10 a) in boiling hexanol and2 c to n-hexyl-3-(tetrahydrothioxo-pyridylamino)-propionate (10 b).     

Kondensierte Heterocyclen aus β-Isothiocyanatoketonen und Aminocarbons?uren

On reaction of glycine, anthranilic acid and anthranilamide respectively with 4-isothiocyanato-4-methyl-2-pentanone (1), derivatives of condensed heterocycles (oxazolopyrimidine5, pyrimidobenzoxazine7 a, pyrimidobenzodiazine7 c) are formed. The same holds for the reaction of dithiocarbamates, prepared from glycine and CS₂ in aqueous NaOH, with 4-methyl-3-penten-2-one and cinnamaldehyde respectively (12 a, b). The reaction of hot dimethylformamide with7 a leads under initial aminolysis to pyrimidine-anthranildimethylamide2 i; this is subsequently transformed partly through methylpyrimidine-pyridine rearrangement into the N-4-pyridine-anthranil-N,N-dimethylamide10 d, partly under further aminolysis byDMF followed by rearrangement to the dimethylaminodihydro-2(1H)-pyridinethione10 c. 5 is converted to dihydro-4-methylamino-2(1H)-pyridinethione (10 a) in boiling hexanol and2 c to n-hexyl-3-(tetrahydrothioxo-pyridylamino)-propionate (10 b).     

Synthetic Ionophores. Part 20: Synthesis and Ionophore Character of 2-Aminothiophenol and 1,3-/1,4-Phenylene Based Silver Selective Receptors

Nucleophilic displacements of 1,3- and 1,4-bis(bromomethyl)benzenes with 2-aminothiophenol provide 1,3- and 1,4- bis(2-aminophenylthiomethyl)benzenes 3 and 11 which undergo intermolecular cyclodehydrochlorination with thiodiglycolyl dichloride and isophthaloyl dichloride to give respectively 6, 8 and 12,13. The diamine 3 and its N,N'-dibenzyl derivative 4 with pyridine-2,6-dicarbonyl dichloride give 7 and 5, respectively. The extraction and transport behaviour of these receptors have been determined towards alkali (Li⁺, Na⁺, K⁺),alkaline earth (Mg²⁺, Ca²⁺, Sr²⁺, Ba²⁺), Tl⁺, Ag⁺ and Pb²⁺ picrates.The participation of various ligating sites in binding have been evaluated through ¹³ NMR studies. The acyclic receptors 3, 4 and 11 show higher Ag⁺ selectivity than the cyclic analogs 6 and 12. In the case of acyclic receptor 3 the organisation induced by the 1,3-phenylene spacer and 2-aminophenylthio units and its flexibility generates optimal binding and selectivity towards Ag⁺. However, in cyclicreceptors 3 and 12 though the three thioether unitsare better organised, the inward placement of the NH_amide units restricts the entry of Ag⁺ into the cavity and lowers both the order of binding and selectivity. The lack of binding ability in 7due to an intramolecular NH_amide–-N_py H-bond isrestored in the N-benzyl derivative 5.     

Synthesis,structural characterization,and in vitro antimicrobial properties of salicylate and pyrazoline complexes of bismuth(III)

Displacement reactions of dichlorobismuth(III)pyrazolinates with oxygen donors such as sodium salicylate and acetate in 1?:?1 and 1?:?2 molar ratio in refluxing anhydrous benzene yields (C₁₂H₁₅N₂OX)Bi(C₆H₄O₃), (CH₃COO)BiCl(C₁₅H₁₂N₂OX), and (CH₃COO)₂Bi(C₁₅H₁₂N₂OX) [C₁₂H₁₅N₂OX?=?3(2′-hydroxyphenyl)-5-(4-X-substituted phenyl) pyrazoline X?=?H in 1,5,9, CH₃ in 2,6,10, OCH₃ in 3,7,11, and Cl in 4,8,12, respectively, (C₆H₄O₃)?=?salicylate and (CH₃COO)?=?acetate]. Newly synthesized derivatives are brown solids, soluble in organic solvents like benzene, chloroform, and acetone. The compounds have been characterized by elemental analyses (C, H, N, Cl, and Bi), molecular weight measurements, and spectral (IR, ¹H NMR, ¹³C NMR) studies. The (C₁₂H₁₅N₂OX) and (C₆H₄O₃) are bidentate while (CH₃COO) is monodentate to bismuth(III), leading to a distorted trigonal bipyramidal structure. The complexes were screened against different bacteria and fungi showing potential antibacterial and antifungal activities.     

Silicon-containing esters of α-cyanoacrylic acid: synthesis and properties

A number of cyanoacetates have been synthesized: cyanoacetoxymethyitrimethylsilane (1), cyanoacetoxymethylpentamethyldisiloxane (2), cyanoacetoxyetoxymethylpentamethyldisiloxane (3). They were converted by the Knoevenagel reaction to novel esters of a-cyanoacrylic acid (4–13) containing silicon atoms in the ester groups and having the general formula RCH=C(CN)COOCH₂X (where R=H, 4-MeOC₆H₄, MeCH=CH, 2-furyl; X=SiMe₃, SiMe₂OSiMe₃, CH₂OCH₂SiMe₂OSiMe₃). These compounds are capable of copolymerization with esters of cyanoacrylic acid which are the precursors to adhesives for cold curing.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 949–952, May, 1993.     

Efficient synthesis of onoceranediol from 12-hydroperoxy-8α,12-epoxy-11-bishomodrimane

An efficient one-step synthesis of the diacetate of the tetracyclic triterpenoid onoceranediol (4) by radical cleavage of the readily available 12-hydroperoxy-8α,12-epoxy-11-bishomodrimane is described. Drim-9(11)-en-8α-yl acetate (7) is formed in this reaction as a byproduct. Onoceranediol diacetate 4 is converted into onoceranediol on treatment with LiAlH₄, and acetate 7 is transformed into drim-9(11)-en-8α-ol on saponification. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2571–2573, November, 2005.     

Acid-Catalysed Dehydration of Tricyclic Unsaturated Alcohols

The tricyclic alcohols 3–7 , derived from the corresponding ketones 1 and 2 (Scheme 1), by action of acids underwent dehydration with skeletal rearrangements. Dehydration of 3 and 4 with POCl₃/pyridine (procedure A) afforded the polycyclic hydrocarbons 9, 10 , and 12, 13 , respectively. With TsOH (procedure B), on the other hand, 3 and 4 gave homo-triquinacenes 10 and 14 respectively, as well as the polycyclic ethers 11 and 15 (Scheme 2). Hydrocarbon 9 (or 12 ) was converted into 10 FSO₃H to the tertiary alcohol 16 (Scheme 4). Plausible mechanisms for these transformations are summarized in Scheme 8. Dehydration of the secondary alcohols 5 and 7 was effected by procedure A. While treatment of alcohol 5 with POCl₃/pyridine yielded two isomeric hydrocarbons 17 and 18 , similar dehydration of its epimeric alcohol 7 afforded hydrocarbon 21 as the sole product. The tertiary alcohol 6 was dehydrated by both procedures to yield two isomeric hydrocarbons 19 and 20 (Scheme 5). Hydrocarbon 20 was converted into 19 by procedure B (mechanisms, Scheme 10). Reaction of ketone 2 with CF₃COOH gave the addition product 22 converted into vinylsulfonyl fluorides 24 and 25 by treatment with FSO₃H (Scheme 6). Homo-triquinacenes 10 and 14 reacted smoothly with 4-phenyl-1,2,4-triazoline-3,5-dione to give the ‘ene’-reaction products 26 and 27 , respectively.     

具有叶绿素-a碳架的(细菌)卟吩衍生物的合成及其共轭区域变化对光谱性能的影响

以脱镁叶绿酸-a甲酯(MP-a) (1)为起始原料, 通过四氧化锇和高碘酸钠的氧化给出3-位乙烯基和13²-位α-氢的氧化产物2和3, 再用四氧化锇继续氧化卟吩醛2则得到细菌卟吩醛4. 经脱甲酸甲酯和硝酸铊氧化, MP-a (1)转化为焦脱镁叶绿酸衍生物5, 将其进一步用四氧化锇氧化则形成细菌卟吩缩醛6. 卟吩醛2在碱性条件下转化为卟吩e₆三甲酯7, 2与烷基溴化镁的格氏反应给出脱镁叶绿酸醇9, 选择高钌酸四丙基铵(TPAP)和N-甲基吗啉N-氧化物将3-位羟基氧化成羰基, 所生成的卟吩二酮10在酸性条件下脱去甲酸甲酯生成焦脱镁叶绿酸衍生物11, 用四氧化锇对7和11实施氧化, 则分别转化为细菌卟吩衍生物8和12. 同时, 讨论了叶绿素衍生物的共轭区域变化对其光谱性能的影响. 所合成的新卟吩和细菌卟吩衍生物均经UV, IR, ¹H NMR及元素分析证明其结构.     

Syntheses and Antimicrobial Activity of Some Novel 6‐Substituted Dibenzo[d,f][1,3,2]dioxaphophepin‐6‐oxides,Sulfides, and Selenides

6‐Substituted‐dibenzo[d, f][1,3,2]dioxaposphepin‐6‐oxides, sulfides, and selenides (5a–i, 6a–d, and 7a–d) were synthesized by reacting 2,2′‐biphenol (1) with phosphorus tribromide in the presence of triethylamine at 0–30°C and subsequent reaction of the monobromide (2) with different Grignard reagents (3) at room temperature. The products (4) were converted to corresponding oxides, sulfides, and selenides (5a–i, 6a–d, and 7a–d) by oxidation with H₂O₂ at room temperature and refluxing with sulfur and selenium respectively. The chemical structures of all the products were confirmed by analytical, IR, NMR (¹H, ¹³C, and ³¹P), and mass spectral data. Most of these compounds exhibited moderate antimicrobial activity.     

Synthesis,spectral study and antimicrobial activity of bismuth(III) 3(2′-hydroxyphenyl)-5-(4-substituted phenyl) pyrazolinates

Dichlorobismuth(III) pyrazolinates and chlorobismuth(III) dipyrazolinates of the type BiCl₂(C₁₅H₁₂N₂OX) and BiCl(C₁₅H₁₂N₂OX)₂ have been synthesized in dry benzene by reaction of BiCl₃ and the sodium salt of pyrazoline in 1 : 1 and 1 : 2 molar ratios at elevated temperature [C₁₅H₁₂N₂OX = 3(2′-hydroxyphenyl)-5-(4-X-substituted phenyl) pyrazoline and X = H in compounds 1, 5, CH₃ in 2, 6, OCH₃ in 3, 7 and Cl in 4, 8, respectively]. These newly synthesized derivatives have been characterized by elemental analysis (C, H, N, Cl and Bi), molecular weight measurements and spectral (IR, ¹H NMR, ¹³C NMR) studies. Selected compounds screened against different bacteria and fungi show potential antibacterial and antifungal activities.     

An Efficient Approach to the Synthesis of Lacto-N-Triosylceramide and Related Substances

Abstract

Hexatriosyl fluorides 3 and 4 were prepared from the known trisaccharides 8 and 13, respectively. These compounds were reacted with the sphingosine derivative 2 to afford coupled products 22 and 25 which, in turn, were converted into the protected glycosphingolipids 23 and 26 after reduction and acylation. Compound 2 was found to be a better substrate than the protected ceramide 1, which had been used previously. Compound 23 was transformed into the lacto-N-triosylceramide 24.     

Study on chemical constituents of an edible mushroom Volvariella volvacea and their antitumor activity in vitro

Abstract

Phytochemical investigation of the fruiting body of Volvariella volvacea led to the isolation of a new furanone, 2(5H)-furanone-4-propionic acid named volvafuranone A (1), together with twelve known compounds (2–13). Compounds 2–7, 9–11 were isolated from this mushroom for the first time. The isolated compounds were assessed for their cytotoxicity against four human tumour lines (SGC-7901, PC-3M, MCF-7, HepG-2), and the results showed that compound 2, 3, 12, 13 have significant cytotoxicity with IC₅₀ values of 5.90?μM (HepG-2), 20.72?μM (HepG-2), 27.98?μM (PC-3M) and 23.15?μM (PC-3M), respectively.     

Synthetic Studies on Sialoglycoconjugates 15: Synthesis of Ganglioside GM3 Analogs Containing A Variety Of Lipophilic Parts

ABSTRACT

Several ganglioside GM₃ analogs, containing a variety of lipophilic parts in place of the ceramide moiety have been synthesized. Glycosylation of (2S, 3R, 4E)-2-azido-3-0-benzoyl-4-octa-decen-l, 3-diol (2) with 0-(methyl 5-acetamido-4, 7, 8, 9-tetra-0-acetyl-3, 5-dideoxy-o-glycero-α-D-galacto-2-nonulopyranosylonate)-(2→3)-(2, 4-di-0-acetyl-6-0-benzoyl-ß-D-galactopyranosyl)-(l→4)-3-(1)-acetyl-2, 6-di-0-benzoyl-α-D-glucopyranosyl trichloroacetimidate (1) gave the 8-glycoside (5), which was converted, via selective reduction of the azide group, introduction of acyl groups, 0-deacylation, and de-esterification, into the desired compounds (10-12). On the other hand, coupling of 1 with 3-benzyloxycarbonyl-amino-1-propanol (3) or (2RS)-3-benzyloxycarbonylamino-2-0-benzoyl-1, 2-propanediol (4) gave the corresponding ß-glycosides 13 and 14, respectively. These were converted by N-debenzyloxycarbonylation, coupling with 2-tetradecylhexadecanoic acid, 0-deacylation, and hydrolysis of the methyl ester group, into the end products (17 and 18).     

Asymmetric Synthesis of Highly Enantiomerically Enriched (S)(-)-β-Bisabolene

(S)-β-Bisabolene, (S)-1, was synthetized by a synthetic route in which (S)-4-methyl-3-cyclohexene carboxylic acid, (S)-10, which was the key intermediate, was prepared via a highly diastereoselective TiCl₄-catalyzed Diels-Alder reaction between isoprene and the acrylate of commercial (R)-pantolactone, followed by hydrolysis. Compound (S)-10 was then converted into ketone (S)-13 using two different procedures. The best one of these, as regards the degree of stereospecificity, involved the reaction of (S)-10 with 2 equiv of 4-methyl-3-penten-1-yllithium, 14, in the presence of CeCl₃, and gave (S)-13 having ca. 84% ee. The Zr-promoted methylenation of this ketone afforded highly enantiomerically enriched (S)-1.