- Invariant and Variable Supramolecular Self-Assembly in 6-Substituted Uracil Derivatives: Insights from X-ray Structures and Quantum Chemical Study
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In this study, three new 6-(arylthio)uracil derivatives, namely, 6-(phenylthio)pyrimidine-2,4(1H,3H)-dione (1), C10H8N2O2S; 6-(p-tolylthio)pyrimidine-2,4(1H,3H)-dione (2), C11H10N2O2S; and 6-(3,5-dimethylphenylthio)pyrimidine-2,4(1H,3H)-dione (3), C12H12N2O2S, have been synthesized. Single-crystal structures of these compounds reveal an invariant molecular tape contains alternate R22(8) synthons formed by N-H···O hydrogen bonds in 1 and 3. This alternate hydrogen-bonded pattern disappeared in 2; instead, a new synthon is generated. The lattice energy calculation suggests that the methyl-substituted derivatives (2 and 3) have high stabilization energy than compound 1. The electrostatic potential map reveals the difference in the accepting tendency of the carbonyl oxygen. The Hirshfeld surface and 2D-fingerprint plots analyses demonstrate that the major intermolecular interactions come from H···O contacts in 1, and these contacts were reduced due to the presence of methyl substitutions in 2 and 3. This reduction is compensated by the increase of the same amount of H···H contacts in these structures. Further, the PIXEL energy and DFT calculations at the M06-2X-D3/cc-pVTZ level of theory were used to characterize the dimeric topology formed in structures of 1-3. The intermolecular interaction energies of dimers calculated by the PIXEL method were compared with the B97D3/def2-TZVP level of approximation. Although these molecules' crystal packing is somewhat different, the energy frameworks show similarities on the respective crystal structure's shortest axis. Furthermore, the nature and strength of various noncovalent interactions such as N-H···O, C-H···O/S/π, π···π, and a chalcogen bond of type C-S···O═C were evaluated using the Bader's quantum theory of atoms-in-molecules framework.
- Abdelbaky, Mohammed S. M.,Al-Wahaibi, Lamya H.,Bysani, Sai Ramya Sree,El-Emam, Ali A.,Garcia-Granda, Santiago,Percino, M. Judith,Tawfik, Samar S.,Thamotharan, Subbiah
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p. 3234 - 3250
(2021/05/29)
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- Efficient synthesis of novel 6-Phenylthio-2,4-disubstituted pyrimidines
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6-Phenylthio-2,4-disubstituted pyrimidines were prepared in five steps starting from barbituric acid. Reaction of barbituric acid with POCl3 in presence of N, N-dimethylaniline furnishes the 2,4,6-trichloropyrimidine, which on reaction with aq. NaOH under reflux yielded the 6-chlorouracil. Reaction of 6-chlorouracil with thiophenol under basic condition furnishes the 6-phenylthiouracil, which on chlorination using excess POCl3 under reflux yielded the key synthon, 6-phenylthio-2,4-dichloropyrimidine. Aromatic nucleophilic substitution reaction of 6-phenylthio-2,4-dichloropyrimidine with a oxygen nucleophile like sodium benzylate and nitrogen nucleophiles like heterocyclic primary amines, aliphatic primary amines and substituted aromatic primary amines furnished the target compounds, 6-phenylthio-2,4-disubstituted pyrimidines respectively in 40-80% yield.
- Goudgaon,Ch, Upendar Reddy
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experimental part
p. 443 - 448
(2010/03/04)
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- Synthesis of substituted uracils by the reactions of halouracils with selenium, sulfur, oxygen and nitrogen nucleophiles under focused microwave irradiation
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Under microwave irradiation, the nucleophilic substitution reactions of halouracils with selenium, sulfur, oxygen and nitrogen nucleophiles was complete within several minutes with yields up to 99%. The method using microwave irradiation is superior to th
- Fang, Woei-Ping,Cheng, Yuh-Tsyr,Cheng, Yann-Ru,Cherng, Yie-Jia
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p. 3107 - 3113
(2007/10/03)
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- Synthesis of certain 6-(arylthio)uracils as potential antiviral agents
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A series of 6-(Arylthio)uracils have been prepared via condensation of 6-chlorouracil or 5-ethyl-6-chlorouracil with the corresponding thiopnenol derivatives in pyridine or ethanolic potassium hydroxide. The synthesized compounds were tested for their antiviral activity. Some of the 5-ethyl-6-(arylthio)uracil derivatives 10a-g showed moderate activities against hepatitis B Virus (HBV) and HIV-1 virus.
- El-Emam, Ali A.,Nasr, Magda N. A.,Pedersen, Erik B.,Fouad, Tarek,Nielsen, Claus
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- Synthesis and anti-HIV activity of acyclic unsaturated C6- and C5-thiophenyl uracil nucleoside and nucleotide analogues
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Acyclic unsaturated C6- and C5-thiophenyl uracil nucleosides and nucleotides, analogues of 1[(2-hydroxyethoxy)methyl]6-(phenylthio)thymine (HEPT), were designed, synthesized and investigated as potential anti-HIV-1 agents in ATH8 cel
- Rajaratnam, Ragine,Phadtare, Shashi
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p. 205 - 209
(2007/10/03)
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- Enzyme inhibitors, their synthesis and methods for use
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Novel compounds are provided that are effective to inhibit the activity of DHUDase or UrdPase. Such compounds have the general formula STR1 where X is S or Se; Y is I, F, Cl, Br, methoxy, benzyl, selenenylphenyl, or thiophenyl, and R1 is an acy
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- Phenylselenenyl- and Phenylthio-Substituted Pyrimidines as Inhibitors of Dihydrouracil Dehydrogenase and Uridine Phosphorylase
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Lithiation of 5-bromo-2,4-bis(benzyloxy)pyrimidine (3) with n-BuLi at -80 deg C followed by the addition of diphenyl diselenide or diphenyl disulfide as an electrophile furnished the corresponding 5-(phenylhetera)-2,4-bis(benzyloxy)pyrimidine, which on ex
- Goudgaon, Naganna M.,Naguib, Fardos N. M.,Kouni, Mahmoud H. el,Schinazi, Raymond F.
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p. 4250 - 4254
(2007/10/02)
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- Synthesis and Properties of 1-Benzothiopyranopyrimidine-2,4-(3H)diones (10-Thia-5-deazaflavins)
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Treatment of 6-arylthiouracils with the Vilsmeier reagent (dimethylformamide-phosphorus oxychloride) gave the corresponding 6-arylthio-5-formyluracils, which could alternatively be prepared by the condensation of 6-chloro-5-formyluracils with thiophenols.Dehydrative cyclization of the above 5-formyluracils with polyphosphoric acid gave 1-benzothiopyranopyrimidine-2,4-(3H)diones (10-thia-5-deazaflavins).These 10-thia-5-deazaflavins oxidized alcohols to give the corresponding carbonyl compounds with the aid of strong base, and they were hydrogenated to 1,5-dihydro-10-thia-5-deazaflavins.Treatment of 10-thia-5-deazaflavins with the concentrated aqueous potassium hydroxide led to the exclusive formation of 1,5-dihydro-10-thia-5-deazaflavins and 1,5-dihydro-10-thia-5-deazaflavins-5-ones via intermolecular oxidation-reduction (disproportionation) between initially formed 1,5-dihydro-5-hydroxy-10-thia-5-deazaflavins and unchanged 10-thia-5-deazaflavins.
- Yoneda, Fumio,Tsukuda, Kinshiro,Kawazoe, Michiko,Sone, Atsuko,Koshiro, Akira
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p. 1329 - 1334
(2007/10/02)
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