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Synthesis and properties of 2-guanidinopurines
2-Guanidinopurines were prepared as derivatives of 2,6-diamino-9-[2- (phosphonomethoxy)ethyl]-9H-purine (PMEDAP) (1), which shows an important antiviral activity. It completes earlier described synthesis of 6-guanidinopurine derivatives. The title compounds were obtained by the reaction of the corresponding 2-chloropurines with guanidine. 2- And 6-guanidinopurines were used as model compounds for determination of dissociation constants (pKa) of their ionogenic groups by capillary zone electrophoresis. The pKa values of ionogenic groups of the above compounds were compared with those of the corresponding aminopurines. The pKa of guanidino group at the purine moiety varies from 7.77 to 10.32. There is no protonation of N1-position in contrast to aminopurines. None of these compounds showed any antiviral activity.
Cesnek, Michal,Masojidkova, Milena,Holy, Antonin,Solinova, Veronika,Koval, Dusan,Kasicka, Vaclav
p. 1303 - 1319
(2006)
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Reduction of different electron-poor N-heteroarylhydrazines in strong basic conditions
The first application of the Wolff-Kishner reduction methodology to electron-poor heteroaromatic compounds is reported. Hydrazino-containing heterocycles with hydrazone-type tautomery have been reduced under basic conditions. This novel chemistry was successfully applied to mono-dehalogenate a number of electron-poor heterocycles in a regioselective manner. According to the experimental results, this reductive process is a base-catalyzed reaction that takes only place in the presence of air, probably through an oxygen-assisted mechanism. As consequence of the specific features of this kind of hydrazone/enehydrazine tautomers, the overall outcome of the process is the synthesis of a Shapirotype reduction product by simply using a milder version of the Huang-Minlon methodology.
Unciti-Broceta, Asier,Pineda De Las Infantas, Maria J.,Gallo, Miguel A.,Espinosa, Antonio
p. 1754 - 1762
(2007)
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Grundmann,Kreutzberger
p. 6559
(1955)
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Multimodal Vacuum-Assisted Plasma Ion (VaPI) Source with Transmission Mode and Laser Ablation Sampling Capabilities
We have developed a multimodal ion source design that can be configured on the fly for various analysis modes, designed for more efficient and reproducible sampling at the mass spectrometer atmospheric pressure (AP) interface in a number of different applications. This vacuum-assisted plasma ionization (VaPI) source features interchangeable transmission mode and laser ablation sampling geometries. Operating in both AC and DC power regimes with similar results, the ion source was optimized for parameters including helium flow rate and gas temperature using transmission mode to analyze volatile standards and drug tablets. Using laser ablation, matrix effects were studied, and the source was used to monitor the products of model prebiotic synthetic reactions. [Figure not available: see fulltext.]
Keelor, Joel D.,Farnsworth, Paul B.,L. Weber, Arthur,Abbott-Lyon, Heather,Fernández, Facundo M.
p. 897 - 907
(2016)
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Guanine, adenine, and hypoxanthine production in UV-irradiated formamide solutions: Relaxation of the requirements for prebiotic purine nucleobase formation
Relaxed requirements: We demonstrate the formation of adenine, hypoxanthine, and guanine from heated (130 °C), UV-irradiated formamide solutions in the absence of an inorganic catalyst. Evidence is also provided that "classical" HCN pathways for purine nucleobase production are also active in heated and UV-irradiated formamide reactions. (Chemical Equation Presented)
Barks, Hannah L.,Buckley, Ragan,Grieves, Gregory A.,Di Mauro, Ernesto,Hud, Nicholas V.,Orlando, Thomas M.
p. 1240-1243+1159
(2010)
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Doerr et al.
p. 3401,3407
(1961)
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Monitoring the reactivity of formamide on amorphous SiO2 by in-situ UV-Raman spectroscopy and DFT modeling
Formamide has been recognized in the literature as a key species in the formation of the complex molecules of life, such as nucleobases. Furthermore, several studies reported the impact of mineral phases as catalysts for its decomposition/polymerization processes, increasing the conversion and also favoring the formation of specific products. Despite the progresses in the field, in situ studies on these mineral-catalyzed processes are missing. In this work, we present an in situ UV-Raman characterization of the chemical evolution of formamide over amorphous SiO2 samples, selected as a prototype of silicate minerals. The experiments were carried out after reaction of formamide at 160 ?C on amorphous SiO2 (Aerosil OX50) either pristine or pre-calcined at 450 ?C, to remove a large fraction of surface silanol groups. Our measurements, interpreted on the basis of density functional B3LYP-D3 calculations, allow to assign the spectra bands in terms of specific complex organic molecules, namely, diaminomaleonitrile (DAMN), 5-aminoimidazole (AI), and purine, showing the role of the mineral surface on the formation of relevant prebiotic molecules.
Balucani, Nadia,Bonino, Francesca,Martra, Gianmario,Pantaleone, Stefano,Signorile, Matteo,Ugliengo, Piero
(2020)
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Silica Metal Oxide Vesicles Catalyze Comprehensive Prebiotic Chemistry
It has recently been demonstrated that mineral self-assembled structures catalyzing prebiotic chemical reactions may form in natural waters derived from serpentinization, a geological process widespread in the early stages of Earth-like planets. We have s
Mattia Bizzarri, Bruno,Botta, Lorenzo,Pérez-Valverde, Maritza Iveth,Saladino, Raffaele,Di Mauro, Ernesto,García-Ruiz, Juan Manuel
p. 8126 - 8132
(2018/05/29)

HETEROCYCLIC COMPOUNDS AND USE THEREOF AS MODULATORS OF TYPE III RECEPTOR TYROSINE KINASES
Provided herein are heterocyclic compounds for treatment of CSF1R, FLT3, KIT, and/or PDGFRβ kinase mediated diseases. Also provided are pharmaceutical compositions comprising the compounds and methods of using the compounds and compositions.
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Paragraph 0714

(2016/08/03)

Solid-supported hydrazone of 4-(4′-Formyl-3′-methoxyphenoxy)butyric acid as a new traceless linker for solid-phase synthesis
The use of a hydrazine derived from a backbone amide linker as a new hydrazone-based traceless linker for solid-phase organic synthesis is described. The stability of the linker was tested under various conditions, including treatment with acids, bases, and borohydrides. Final compounds can be released by selective cleavage using trimethylsilanolate. To demonstrate the versatility of the linker, the synthesis of a model compound under various reaction conditions was performed with good results.
Okorochenkov, Sergei,Burglova, Kristyna,Popa, Igor,Hlavac, Jan
supporting information
p. 180 - 183
(2015/01/30)

Method For Preparing Nitrogen Compounds
The present invention relates to a method for preparing nitrogen compounds using carbon dioxide, and to the use of the method in the production of vitamins, pharmaceutical products, adhesives, acrylic fibres, synthetic leathers, pesticides, herbicides, antifungal agents and fertilisers. The invention also relates to a method for producing vitamins, pharmaceutical products, adhesives, acrylic fibres, synthetic leathers, pesticides, herbicides, antifungal agents and fertilisers, which includes a step of preparing nitrogen compounds using the method of the invention. The invention further relates to a method for preparing labelled nitrogen compounds using carbon dioxide and to the uses thereof.
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Paragraph 0.192; 0193

(2015/06/03)

Meteorites as catalysts for prebiotic chemistry
From outer space: Twelve meteorite specimens, representative of their major classes, catalyse the synthesis of nucleobases, carboxylic acids, aminoacids and low-molecular-weight compounds from formamide (see figure). Different chemical pathways are identified, the yields are high for a prebiotic process and the products come in rich and composite panels.
Saladino, Raffaele,Botta, Giorgia,Delfino, Michela,Di Mauro, Ernesto
p. 16916 - 16922
(2014/01/06)

Complete Catalytic Deoxygenation of CO2 into Formamidine Derivatives
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Jacquet, Olivier,DasNevesGomes, Christophe,Ephritikhine, Michel,Cantat, Thibault
p. 117 - 120
(2013/03/28)

A method for the reductive scission of heterocyclic thioethers
A mild, chemoselective, and generally high-yielding method for the reductive scission of heterocyclic thioethers is described. Suitable heterocycles have a thioether substituent at the 2-position relative to a ring heteroatom. The convenient and straightforward method is demonstrated with reactants which are not compatible with the standard Raney nickel conditions such as sulfides, sulfones, and thiophenes. In addition, benzyl esters, benzyl amides, and benzyl carbamates are tolerated by the reductive reaction conditions.
Graham, Thomas H.,Liu, Wensheng,Shen, Dong-Ming
supporting information; experimental part
p. 6232 - 6235
(2012/01/03)

NOVEL AROMATIC COMPOUND AND POLYARYLENE COPOLYMER HAVING NITROGEN-CONTAINING HETEROCYCLE INCLUDING SULFONIC ACID GROUP IN SIDE CHAIN
Provided is a solid polymer electrolyte having increased heat resistance and high proton conductivity and a proton conductive membrane composed of the electrolyte. Also provided is a copolymer having a sulfonic acid group. The copolymer includes a repeating unit represented by Formula (1): (in the formula, Y denotes at least one kind of structure selected from the group consisting of —CO—, —SO2—, —SO—, —CONH—, —COO—, —(CF2)l— (l is an integer of 1 to 10), and —C(CF3)2—; W denotes at least one kind of structure selected from the group consisting of a direct bond, —CO—, —SO2—, —SO—, —CONH—, —COO—, —(CF2)l— (l is an integer of 1 to 10), —C(CF3)2—, —O—, and —S—; Z denotes a direct bond or at least one kind of structure selected from the group consisting of —(CH2)l—(l is an integer of 1 to 10), —C(CH3)2—, —O—, —S—, —CO—, and —SO2—; R30 denotes a nitrogen-containing aromatic ring having a substituent represented by —SO3H, —O(CH2)hSO3H, or —O(CF2)hSO3H (h is an integer of 1 to 12); p is an integer of 0 to 10; q is an integer of 0 to 10; r is an integer of 1 to 5; and k is an integer of 0 to 4).
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(2010/06/22)

HAIR TREATMENT PRODUCTS COMPRISING POLYMERS
The invention relates to hair treatment products, comprising at least one copolymer made of 0.1 to 50% (in relation to the total number of monomers in the copolymer) monomers of the formula (I), wherein the unknowns are defined as in claim 1, and A2) are monomers from the group of acrylic acid, methacrylic acid and the like, and—optionally non-ionic monomers from the group of acrylamide, vinyl alcohol, and the like, wherein the monomers A2 and A3 together represent 50 to 99.9% (in relation to the total number of monomers in the copolymer) of the copolymer, at least one silicon and at least one selected care product, wherein the products result in advantageous effects for skin and hair.
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(2009/12/24)

Synthesis and degradation of nucleic acid components by formamide and iron sulfur minerals
We describe the one-pot synthesis of a large panel of nucleic bases and related compounds from formamide in the presence of iron sulfur and iron-copper sulfur minerals as catalysts. The major products observed are purine, 1H-pyrimidinone, isocytosine, adenine, 2-aminopurine, carbodiimide, urea, and oxalic acid. Isocytosine and 2-aminopurine may recognize natural nucleobases by Watson-Crick and reverse Watson-Crick interactions, thus suggesting novel scenarios for the origin of primordial nucleic acids. Since the major problem in the origin of informational polymers is the instability of their precursors, we also investigate the effects of iron sulfur and iron-copper sulfur minerals on the stability of ribooligonucleotides in formamide and in water. All of the iron sulfur and iron-copper sulfur minerals stimulated degradation of RNA. The relevance of these findings with respect to the origin of informational polymers is discussed.
Saladino, Raffaele,Neri, Veronica,Crestini, Claudia,Costanzo, Giovanna,Graciotti, Michele,Di Mauro, Ernesto
experimental part
p. 15512 - 15518
(2009/03/12)

Small molecule compositions for binding to hsp90
Structural differences in binding pockets of members of the HSP90 family can be exploited to achieve differential degradation of kinases and other signaling proteins through the use of designed small molecules which interact with the N-terminal binding pocket with an affinity which is greater than ADP and different from the ansamycin antibiotics for at least one species of the HSP90 family. Moreover, these small molecules can be designed to be soluble in aqueous media, thus providing a further advantage over the use of ansamycin antibiotics. Pharmaceutical compositions can be formulated containing a pharmaceutically acceptable carrier and a molecule that includes a binding moiety which binds to the N-terminal pocket of at least one member of the HSP90 family of proteins. Such binding moieties were found to have antiproliferative activity against tumor cells which are dependent on proteins requiring chaperones of the HSP90 family for their function. Different chemical species have different activity, however, allowing the selection of, for example Her2 degradation without degradation of Raf kinase. Thus, the binding moieties possess an inherent targeting capacity. In addition, the small molecules can be linked to targeting moieties to provide targeting of the activity to specific classes of cells. Thus, the invention further provides a method for treatment of diseases, including cancers, by administration of these compositions. Dimeric forms of the binding moieties may also be employed.
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(2008/06/13)

Nucleotide triphosphates and their incorporation into oligonucleotides
The present invention relates to novel nucleotide triphosphates, methods of synthesis and process of incorporating these nucleotide triphosphates into oligonucleotides, and isolation of novel nucleic acid catalysts (e.g., ribozymes or DNAzymes). Also, provided are the use of novel enzymatic nucleic acid molecules to inhibit HER2/neu/ErbB2 gene expression and their applications in human therapy.
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(2008/06/13)

Purine derivatives having phosphodiesterase iv inhibition activity
Disclosed are compounds of the formula: whereinR3, R6a, R6b and R8 are substituted as disclosed herein. The compounds are effective in effecting PDE IV inhibition in patients in need thereof.
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(2008/06/13)

PURINE DERIVATIVES HAVING PHOSPHODIESTERASE IV INHIBITION ACTIVITY
A compound of the formula: wherein R2 is O or S; R3, R6a and R8 are the same or different and each represent a C1-8 alkyl which is unbranched or branched and unsubstituted or substituted with OH, alkoxy, CO2H, =NOH, =NOCONH2, or =O; C3-8 cycloalkyl which is unsubstituted or substituted with OH, alkoxy, CO2H, =NOH, =NOCONH2, or =O; C4-8 cycloalkylalkyl wherein the cycloalkyl portion is unsubstituted or substituted with OH, alkoxy, CO2H, =NOH, =NOCONH2, or =O; aryl which is unsubstituted or substituted with Cl, NH2, alkylamino, dialkylamino, amido, C1-C8 alkylamido, C1-C3 dialkylamido, OH, alkoxy, HC=NOH, HC=NOCONH2, C1-C3 alkyl, phenyl or benzyl; aralkyl (C1-4); heterocyclyl; heterocyclylalkyl (C1-C4); and heteroaryl; R6b represents a H or R6a, or together R6b, N, and R6a make a 3 to 8 member ring containing at least one carbon, from one to three nitrogen atoms, from zero to two oxygen atoms, from zero to two sulfur atoms, said ring optionally substituted with alkoxy, CO2H, CONH2, =NOH, =NOCONH2, =O; and where aryl is phenyl or naphthyl, the heterocyclyl is a 5, 6 or 7 membered ring including from one to three nitrogen atoms, and from zero to two oxygen atoms, from zero to two sulfur atoms, and can be substituted as in aryl on the carbons or nitrogens of that ring; or a pharmaceutically acceptable salt thereof, provided that when R3 is propyl, R8 is not cyclopentyl, noradamantyl, or dicyclopropylmethyl.
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(2008/06/13)

Purine derivatives having phosphodiesterase IV inhibition activity
A compound of the formula: wherein R3represent a C1-8alkyl which is unbranched or branched and unsubstituted or substituted with OH, alkoxy, CO2H, ═NOH, ═NOCONH2, or ═O; C3-8cycloalkyl which is unsubstituted or substituted with OH, alkoxy, CO2H, ═NOH, ═NOCONH2, or ═O; C4-8cycloalkylalkyl wherein the cycloalkyl portion is unsubstituted or substituted with OH, alkoxy, CO2H, ═NOH, ═NOCONH2, or ═O; aryl which is unsubstituted or substituted with Cl, NH2, alkylamino, dialkylamino, amido, C1-C8alkylamido, C1-C3dialkylamido, OH, alkoxy, HC═NOH, HC═NOCONH2, C1-C3alkyl, phenyl or benzyl; aralkyl (C1-4); heterocyclyl; heterocyclylalkyl (C1-C4); and heteroaryl; R8represents H or a C1-8alkyl which is unbranched or branched and unsubstituted or substituted with OH, alkoxy, CO2H, ═NOH, ═NOCONH2, or ═O; C3-8cycloalkyl which is unsubstituted or substituted with OH, alkoxy, CO2H, ═NOH, ═NOCONH2, or ═O; C4-8cycloalkylalkyl wherein the cycloalkyl portion is unsubstituted or substituted with OH, alkoxy, CO2H, ═NOH, ═NOCONH2, or ═O; aryl which is unsubstituted or substituted with Cl, NH2, alkylamino, dialkylamino, amido, C1-C8alkylamido, C1-C3dialkylamido, OH, alkoxy, HC═NOH, HC═NOCONH2, C1-C3alkyl, phenyl or benzyl; aralkyl (C1-4); heterocyclyl; heterocyclylalkyl (C1-C4); and heteroaryl.
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(2008/06/13)

Heterocyclic compounds
The present invention relates to a heterocyclic compound of the following general formula (I): wherein X is sulfur atom, oxygen atom or —NR3— (R3may form a heterocyclic ring or a substituted heterocyclic ring with R1via the nitrogen atom), R1is alkyl group, substituted alkyl group, aryl group, substituted aryl group, heterocyclic group or substituted heterocyclic group, and R2is hydrogen atom, halogen atom etc.; or its pharmaceutically acceptable salt and interferon inducers, antiviral agents, anticancer agents and therapeutic agents for immunologic diseases comprising the compound (I) or its pharmaceutically acceptable salt as active ingredients.
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(2008/06/13)

A possible prebiotic synthesis of purine, adenine, cytosine, and 4(3H)-pyrimidinone from formamide: Implications for the origin of life
The synthesis of prebiotic molecules is a major problem in chemical evolution as well as in any origin-of-life theory. We report here a plausible new prebiotic synthesis of naturally occurring purine and pyrimidine derivatives from formamide under catalytic conditions. In the presence of CaCO3 and different inorganic oxides, namely silica, alumine, kaolin, and zeolite (Y type), neat formamide undergoes the formation of purine, adenine, cytosine, and 4(3H)-pyrimidinone, from acceptable to good yields. The role of catalysts showed to be not limited to the improvement of the yield but it is also relevant in providing a high selectivity in the products distribution.
Saladino, Raffaele,Crestini, Claudia,Costanzo, Giovanna,Negri, Rodolfo,Di Mauro, Ernesto
p. 1249 - 1253
(2007/10/03)

Aryl and heteroaryl purine compounds
Novel bicyclic condensed pyrimidine compounds having general formula (I) STR1 wherein X is --CH2 --, --NH--(CH2)n --, --O--(CH2)n -- or --S--(CH2)n -- in which n is zero or 1; A is a 4,5-fused imidazole ring N-substituted by R3 which is hydrogen, C1 -C4 alkyl or benzyl, or A is a 2,3-fused pyridine ring C-substituted by R4 which is hydrogen, C1 -C4 alkyl, C1 -C4 alkoxy, halogen or NR5 R6 in which each of R5 and R6 independently is H or C1 -C4 alkyl; B is a bicyclic ring chosen from tetralin, indane and 2-oxindole; each of R1 and R2 independently is hydrogen, C1 -C4 alkyl, halogen, hydroxy, C1 -C4 alkoxy, C1 -C4 alkoxycarbonyl, nitro, cyano or CF3 ; and the pharmaceutically acceptable salts thereof.
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(2008/06/13)

Ethaden synthesis
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Kochergin,Yakovleva,Persanova,Aleksandrova
p. 327 - 330
(2007/10/03)

Palladium catalyzed nucleoside modifications methods using nucleophiles and carbon monoxide
This invention discloses a method for the preparation modified nucleosides using a palladium catalyst, a nucleophile and carbon monoxide.
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(2008/06/13)

Lipophilic, aminohydrolase-activated prodrugs
The present invention relates, in general, to prodrugs. In particular, the present invention relates to lipophilic, aminohydrolase-activated, anti-viral nucleoside prodrug compounds, pharmaceutical compositions containing these compounds, and methods of using these compounds.
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(2008/06/13)

2'-Deoxy-2',2'-difluoro(2,6,8-substituted) purine nucleosides having anti-viral and anti-cancer activity and intermediates
2-Deoxy-2,2-Difluoro (2,6,8-Substituted) Purine Nucleosides Having Anti-Cancer and Anti-Viral Activity and Intermediates.
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(2008/06/13)

Artificial DNA base pair analogues
The present invention is directed to new artificial base pairs comprising complementary artificial purines and pyrimidines and methods of using artificial complementary base pairs.
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(2008/06/13)

N23-ethenoguanosine and IA′-metamorphosine: 5N NMR spectroscopy and elucidation of physico-chemical properties by kinetic and equilibrium measurements
Tautomerism, protonation and electronic properties of the base moieties of IA′-metamorphosine (1a), N2,3-ethenoguanosine (2a) and O6-benzyl-N2,3-ethenoguanosine (3a were investigated by 15N NMR spectroscopy. pKa values of the same compounds were determined spectrophotometrically, and hydrolytic stability of the N-glycosidic bond was studied at various hydronium ion concentrations. The base stacking ability and metal ion complexation of N2,3-ethenoguanosine and its 9-ethyl counterpart (7) were elucidated by phase distribution and potentiometric measurements.
Glemarec, Corine,Besidsky, Yevgeny,Chattopadhyaya, Jyoti,Kusmierek, Jaroslaw,Lahti, Marjo,Oivanen, Mikko,Loennberg, Harri
p. 6689 - 6704
(2007/10/02)

Deoxyfluoronucleoside process
There is disclosed a process for synthesizing 2?--fluoro-2?,3?-dideoxyarabinofuranose derivatives of inosine and adenine on a large scale which involves coupling of a fluorosugar derivative and a purine reactant to provide a purine nucleoside intermediate which is then deoxygenated. 6-Chloro or 6-benzamidopurine and 1,3,5-tri-O-benzoyl-2--deoxy-2-fluoroarabinofuranose are used as starting materials.
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(2008/06/13)

2-substituted inosines and their use as antiviral agents
Certain functionalized inosines, preferably C2 alkylated inosines, are prepared as new compounds having use as antiviral agents against viruses.
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(2008/06/13)

3-deazaneplanocin, intermediates for it, and antiviral composition and method of treatment using it
The new compound 3-deazaneplanocin A has been discovered to have potent anti-viral, anti-tumor activity and differentiating activity. A simple method for preparing 3-deazaneplanocin A has been developed involving nucleophilic substitution, which method can also be used to prepare a great variety of carbocyclic nucleosides.
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(2008/06/13)

Antiviral and anticancer cyclopentenyl cytosine
Cyclopentenyl pyrimidine compounds have potent anti-viral, anti-tumor and differentiating activity. Of these compounds, cyclopentenyl cytosine has proved to be particularly effective in a variety of tumors, as well as having good antiviral activity and potent differentiating properties.
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(2008/06/13)

Hydrolysis of Dideoxygenated Purine Nucleosides: Effect of Modification of the Base Moiety
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Nair, Vasu,Buenger, Greg S.
p. 3695 - 3697
(2007/10/02)

ACIDIC HYDROLYSIS OF 6-SUBSTITUTED 9-(2-DEOXY-β-D-ERYTHRO-PENTOFURANOSYL)PURINES AND THEIR 9-(1-ALKOXYETHYL) COUNTERPARTS: KINETICS AND MECHANISM.
The rate constants for the hydrolysis of several 6-substituted 9-(2-deoxy-β-D-erythro-pentofuranosyl)purines and 9-(1-alkoxyethyl)purines have been measured at different concentrations of oxonium ion.The effects that varying the polar nature of the alkoxy group exerts on the hydrolysis of unsubstituted 9-(1-alkoxyethyl)purines are interpreted to indicate that the reaction proceeds by a rate-limiting departure of the protonated base moiety with a concomitant formation of an alkoxyethyl oxocarbenium ion.The same mechanism is applied to the hydrolysis of 9-(2-deoxy-β-D-erythro-pentofuranosyl)purines by comparing the influences that 6-substituents have on the reactivity of these compounds and their 9-(1-alkoxyethyl) counterparts.No sign of anomerisation was detected, when the hydrolysis of 2'-deoxyadenosine was followed by 1H NMR spectroscopy.
Oivanen, Mikko,Loennberg, Harri,Zhou, Xiao-xiong,Chattopadhyaya, Jyoti
p. 1133 - 1140
(2007/10/02)

A 15N-STUDY ON THE DEAMINATION OF 1-AMINOPURINIUM SALTS WITH AMINES
Reaction of 1-aminoadenosinium mesitylenesulphonate, 1a, with methanolic ammonia for 10 h at 80 deg C yields adenosine, 7a, and nebularine, 6a.With methanolic methylamine 1a gives 6-methylamino-9-β-D-ribofuranosylpurine, 8a, and adenosine, 7a, respectively.Similar results are obtained with the salt of 1-amino-2',3'-O-isopropylideneadenosine, 1b. 1-Aminoadeninium mesitylenesulphonate, 1c, with methanolic methylamine only yields 6-(methylamino)purine, 8c.In contrast, the mesitylenesulphonate salt of 1,2-diaminopurine, 11, with methanolic methylamine gives only deamination at N1, affording 2-aminopurine, 12.Studies with 15N-labelled methanolic ammonia or 15N-labelled purinium compounds show that in all these reactions, except that of 11, a ring-opening mechanism (ANRORC-mechanism) is involved.
Kos, Nico J.,Jongejan, Hugo,Plas, Henk C. van der
p. 369 - 374
(2007/10/02)

DEAMINATION, INVOLVING RING OPENING, IN REACTIONS OF 1-AMINOPURINIUM MESITYLENESULFONATES WITH METHANOLIC AMMONIA
On reaction of 1-aminopurinium mesitylenesulfonates with methanolic ammonia N-deamination occurs.For 1-amino-, 1-amino-8-(methylthio)-, 1-amino-8-phenyl-, 1-amino-2-methyl-, 1-amino-6-methyl- and 1-amino-8-phenyl-9-methylpurinium mesitylenesulfonate this reaction proceeds for at least 75percent via ring opening as shown by the isolation of 1-15N-labelled purines when 15N-labelled methanolic ammonia was used. 1-Amino-9-methylpurinium mesitylenesulfonate gave N-deamination without ring opening.The reaction of 1-amino-6-(methylthio)purinium mesitylenesulfonate with methanolic ammonia involves, besides deamination, partial substitution of the methylthio group; no ring opening is involved.However, ring opening followed by substitution occurs in the reaction of 1-amino-2-(methylthio)purinium mesitylenesulfonate; the reaction proceeds via an adduct at position 2.
Kos, N. J.,Jongejan, H.,van der Plas, H. C.
p. 4841 - 4848
(2007/10/02)

N6 -dihydroxypropyladenosines
N6 -Dihydroxypropyladenosines and pharmaceutically acceptable acid addition salts having highly desirable central nervous system properties, processes for their manufacture and pharmaceutical compositions and methods for using said compounds and compositions are described.
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(2008/06/13)

A 15N study of the ammonia-induced deamination of 1-aminopurinium salts
Reaction of 1-aminoadeninium mesitylenesulfonate (1) and 1,2-diaminopurinium mesitylenesulfonate (8) with methanolic ammonia for 17 h at 100 deg C leads to deamination at N(1), yielding adenine and 2-aminopurine, respectively, as well as dideamination, yielding purine.It is very likely that 6-hydrazinopurine is formed in the dideamination of 1 and that 2- hydrazinopurine is an intermediate in the dideamination of 8.From both hydrazinopurines, purine is formed.Labelling studies, using 15N-labelled methanolic ammonia, show that, in the deamination reactions, a ring-opening reaction (ANRORC mechanism) is involved.
Jongejan, H.,Kos, N. J.,Plas, H. C. van der
p. 337 - 340
(2007/10/02)

Mechanisms for the Solvolytic Decomposition of Nucleoside Analogues. XI. Competitive Pathways for the Acidic Hydrolysis of 9-(β-D-Ribofuranosyl)purine
Kinetics and product distributions of the hydrolysis of 9-(β-D-ribofuranosyl)purine have been examined over a wide acidity range.At high oxonium ion concentrations rate-limiting departure of the mono- and diprotonated purinyl group with concomitant formation of a glycosyl oxocarbenium ion constitutes the major reaction pathway, analogous to the hydrolysis of 6-substituted purine nucleosides.In slightly acidic solutions opening of the imidazole ring of the base moiety prevails, and 4-amino-5-formamidopyrimidine, formed as a relatively stable intermediate, undergoes further hydrolysis to 4,5-diaminopyrimidine or cyclization to purine, the product composition depending on the acidity of the reaction solution.Rate constants for the partial reactions have been calculated and the mechanisms of the individual steps are discussed.
Loennberg, Harri,Heikkinen, Erkki
p. 673 - 678
(2007/10/02)

Reaction of 9-(β-D-Ribofuranosyl)purine with Alkalies: Kinetics and Mechanism
The progress
Loennberg, Harri,Lehikoinen, Pertti
p. 4964 - 4969
(2007/10/02)

MODELS OF FOLATE COENZYMES-VII SYNTHESIS AND CARBON TRANSFER REACTIONS OF N5,N10-METHENYL AND N5,N10-METHYLENETETRAHYDROFOLATE MODELS
Carboxylate esters react with 1,2-diaminoethanes to yield imidazolines, which upon consecutive reaction with acetic anhydride or tosyl chloride and methyl iodide give imidazolinium salts that serve as models of N5,N10-(CH+)-tetrahydrofolate (THF) coenzymes (7a,b and 18a,b).Reduction of the latter salts with sodium borohydride or reaction with anions (R-) give the corresponding 5,10--THF models.Mono- and bifunctional nucleophiles react with 18a,b to yield carbon-transfer products. 6-Alkylamino-1,3-dimethyluracils react with 1-tosyl-3,4,4-trimethylimidazolidine (the reduction product of 18b), in the presence of acetic acid, to form carbon-transfer products via a mechanism which bears close analogy to the mechanism of action of thymidylate synthetase.
Bieraeugel, H.,Plemp, R.,Hiemstra, H. C.,Pandit, U. K.
p. 3971 - 3980
(2007/10/02)