Tag: M.W=100-150

Burrow, P. D. published the artcileVibrational Feshbach resonances in uracil and thymine, Formula: C5H6N2O2, the publication is Journal of Chemical Physics (2006), 124(12), 124310/1-124310/7, database is CAplus and MEDLINE.

Sharp peaks in the dissociative electron attachment (DEA) cross sections of uracil and thymine at energies below 3 eV are assigned to vibrational Feshbach resonances (VFRs) arising from coupling between the dipole bound state and the temporary anion state associated with occupation of the lowest σ^* orbital. Three distinct vibrational modes are identified, and their presence as VFRs is consistent with the amplitudes and bonding characteristics of the σ^* orbital wave function. A deconvolution method is also employed to yield higher effective energy resolution in the DEA spectra. The site dependence of DEA cross sections is evaluated using Me substituted uracil and thymine to block H atom loss selectively. Implications for the broader issue of DNA damage are briefly discussed.

Journal of Chemical Physics published new progress about 608-34-4. 608-34-4 belongs to pyrimidines, auxiliary class Pyrimidine,Amide, name is 3-Methylpyrimidine-2,4(1H,3H)-dione, and the molecular formula is C5H6N2O2, Formula: C5H6N2O2.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia

Li, Xue-Dong published the artcileA NaI/H₂O₂-Mediated Sulfenylation and Selenylation of Unprotected Uracil and Its Derivatives, Application of 3-Methylpyrimidine-2,4(1H,3H)-dione, the publication is Organic Letters (2019), 21(17), 6643-6647, database is CAplus and MEDLINE.

An efficient iodide-catalyzed/hydrogen peroxide mediated sulfenylation and selenylation of unprotected uracil and its derivatives with simple thiols and diselenides was established. This coupling tolerates a broad variety of functional groups to provide diverse 5-sulfur/selenium-substituted uracil derivatives in good to excellent yields (up to 93%).

Organic Letters published new progress about 608-34-4. 608-34-4 belongs to pyrimidines, auxiliary class Pyrimidine,Amide, name is 3-Methylpyrimidine-2,4(1H,3H)-dione, and the molecular formula is C5H6N2O2, Application of 3-Methylpyrimidine-2,4(1H,3H)-dione.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia

Kheifets, G. M. published the artcileEffect of the structure of 1- and 3-methylpyrimidin-4-ones on the rate of nucleophilic substitution of the 2-methylsulfanyl group, Synthetic Route of 608-34-4, the publication is Russian Journal of Organic Chemistry (Translation of Zhurnal Organicheskoi Khimii) (2004), 40(1), 104-113, database is CAplus.

Rate constants for substitution of the 2-methylsulfanyl group in 1- and 3-methyl-2-methylsulfanylpyrimidin-4-ones and their 5-fluoro analogs were measured in the reaction with butylamine, alk. hydrolysis, and methanolysis. The rate of substitution in 1-Me isomers having a zwitterionic structure is greater by a factor of ∼2 than the rate of substitution in 3-Me isomers with conjugated double bonds in the ring. The presence of a fluorine atom in position 5 accelerates nucleophilic substitution in 1-Me isomers, while 5-fluoro-3-methyl-2-methylsulfanylpyrimidin-4-ones react at a lower rate than their 5-unsubstituted analogs. According to the NMR data, the reactions involve formation of a tetrahedral intermediate. Anchimeric effect of the Me group on N¹ hampers attack by basic reagent on the C⁶ atom.

Russian Journal of Organic Chemistry (Translation of Zhurnal Organicheskoi Khimii) published new progress about 608-34-4. 608-34-4 belongs to pyrimidines, auxiliary class Pyrimidine,Amide, name is 3-Methylpyrimidine-2,4(1H,3H)-dione, and the molecular formula is C5H6N2O2, Synthetic Route of 608-34-4.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia

Cruege, Francis published the artcileBasic properties of dimethylamino derivatives of pyridine and pyrimidine, Recommanded Product: N,N-Dimethylpyrimidin-4-amine, the publication is Bulletin de la Societe Chimique de France (1970), 3889-94, database is CAplus.

A correlation exists between the free enthalpy of complexation (with PhOH) and the intrinsic pKa of (dimethylamino)pyridines and -pyrimidines. 2-Dimethylamino isomers are the most basic compounds, and the steric hindrance effect of the 2-dimethylamino group is discussed.

Bulletin de la Societe Chimique de France published new progress about 31401-45-3. 31401-45-3 belongs to pyrimidines, auxiliary class Pyrimidine,Amine, name is N,N-Dimethylpyrimidin-4-amine, and the molecular formula is C6H9N3, Recommanded Product: N,N-Dimethylpyrimidin-4-amine.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia

El-Ghomari, K. published the artcileMetabolic N-oxygenation of 2,4-diamino-6-substituted pyrimidines, Synthetic Route of 74638-76-9, the publication is European Journal of Drug Metabolism and Pharmacokinetics (1987), 12(4), 253-8, database is CAplus and MEDLINE.

Biol. oxidation of 2,4-diamino-6-substituted pyrimidines was studied using hepatic microsomes from various mammalian species. The 3-N-oxides were formed with 6-pipeidino-, 6-diethylamino-, 6-methyl-, and 6-chloro-substituted 2,4-diaminopyrimidines: no evidence of 1-N-oxide formation was obtained. With the 6-hydroxy-, 6-amino-, and unsubstituted 2,4-diaminopyrimidines and melamine, no N-oxidative metabolite was detected. The differences in N-oxide formation is discussed in terms of the effect of substituents on tautomerism and electron distribution. The N-oxygenation was mediated via a cytochrome P 450-dependent system.

European Journal of Drug Metabolism and Pharmacokinetics published new progress about 74638-76-9. 74638-76-9 belongs to pyrimidines, auxiliary class Pyrimidine, name is 2,4-Diaminopyrimidine-3-oxide, and the molecular formula is C4H6N4O, Synthetic Route of 74638-76-9.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia

Ptasinska, Sylwia published the artcileBond- and Site-Selective Loss of H^– from Pyrimidine Bases, Application In Synthesis of 608-34-4, the publication is Physical Review Letters (2005), 95(9), 093201/1-093201/4, database is CAplus and MEDLINE.

Electron attachment to gas phase thymine and uracil leads to H^– loss within a broad and structured feature in the energy range between about 5 and 12 eV consisting of 4 overlapping resonances. By using thymine and uracil methylated at the N1 and N3 positions, resp., and taking into account recent results from partly deuterated thymine, we find that by tuning the electron energy, H^– loss turns out to be not only bond selective, i.e., (C-H) vs. (N-H) bonds, but also site selective (N1 vs. N3 site). Such a bond and site selectivity by energy has not been observed before in dissociative electron attachment. Implications for the mechanism of strand breaks observed in plasmid DNA are considered.

Physical Review Letters published new progress about 608-34-4. 608-34-4 belongs to pyrimidines, auxiliary class Pyrimidine,Amide, name is 3-Methylpyrimidine-2,4(1H,3H)-dione, and the molecular formula is C5H6N2O2, Application In Synthesis of 608-34-4.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia

Ptasinska, Sylwia published the artcileBond- and site-selective loss of H atoms from nucleobases by very-low-energy electrons (< 3 eV), Formula: C5H6N2O2, the publication is Angewandte Chemie, International Edition (2005), 44(42), 6941-6943, database is CAplus and MEDLINE.

When excess charge is deposited on thymine and uracil by resonant attachment of low-energy electrons (0-3 eV), H atoms are cleaved exclusively from the N positions. This bond selectivity can be made site selective (N1 vs. N3 position) by properly tuning the electron energy. This conclusion was drawn from experiments with methylated thymine and uracil (see picture) in crossed beam experiments

Angewandte Chemie, International Edition published new progress about 608-34-4. 608-34-4 belongs to pyrimidines, auxiliary class Pyrimidine,Amide, name is 3-Methylpyrimidine-2,4(1H,3H)-dione, and the molecular formula is C5H6N2O2, Formula: C5H6N2O2.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia

Prakash, Anjanappa published the artcileEfficient indoles and anilines syntheses employing tert-butyl sulfinamide as ammonia surrogate, Application of 5-Aminopyrimidine-2-carbonitrile, the publication is Tetrahedron Letters (2011), 52(43), 5625-5628, database is CAplus.

Tert-Bu sulfinamide is an ammonia equivalent for the palladium-catalyzed amination of aryl bromides and aryl chlorides. Using these amine derivatives, it has been observed that substituted indoles and anilines with sensitive functional groups can be readily prepared This surrogate has also been used for the synthesis of indoles from (2-bromophenyl)ethynes using palladium-catalyzed cross coupling reaction as the key step.

Tetrahedron Letters published new progress about 56621-93-3. 56621-93-3 belongs to pyrimidines, auxiliary class Pyrimidine,Nitrile,Amine, name is 5-Aminopyrimidine-2-carbonitrile, and the molecular formula is C5H4N4, Application of 5-Aminopyrimidine-2-carbonitrile.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia

Feuerstein, Marie published the artcileSonogashira reaction of heteroaryl halides with alkynes catalyzed by a palladium-tetraphosphine complex, SDS of cas: 174456-28-1, the publication is Journal of Molecular Catalysis A: Chemical (2006), 256(1-2), 75-84, database is CAplus.

Cis,cis,cis-1,2,3,4-Tetrakis(diphenylphosphinomethyl)cyclopentane/(1/2)[PdCl(C₃H₅)]₂ system catalyzes the Sonogashira reaction of heteroaryl halides with a range of alkynes with moderate to high substrate/catalyst ratios in good yields. A variety of heteroaryl halides such as pyridines, quinolines, a pyrimidine, an indole, thiophenes, or a thiazole have been used successfully. The reaction also tolerates several alkynes such as phenylacetylene and alk-1-ynols. The nature of the heteroaromatics and the substituent of the alkynes have both an important effect on the reaction rates. High reaction rates were generally observed with phenylacetylene. With this alkyne substrate/catalyst ratios up to 10,000 have been used successfully. An effect of the position of the alc. function on the reaction rates was observed with alk-1-ynols. Higher substrate/catalyst ratios could be used with but-3-yn-1-ol, pent-4-yn-1-ol or hex-5-yn-1-ol than with propargyl alc. The nature and the position of the halide on the heteroaromatics have also an important effect on the reaction rates. As expected, higher reaction rates were obtained with heteroaryl iodides than with heteroaryl bromides or chlorides.

Journal of Molecular Catalysis A: Chemical published new progress about 174456-28-1. 174456-28-1 belongs to pyrimidines, auxiliary class Pyrimidine,Alkynyl,Alcohol, name is 3-(Pyrimidin-5-yl)prop-2-yn-1-ol, and the molecular formula is C7H6N2O, SDS of cas: 174456-28-1.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia

Ackermann, H. published the artcileConstitution and reactivity of trichloropyrimidylamino derivatives, Category: pyrimidines, the publication is Helvetica Chimica Acta (1962), 1683-98, database is CAplus.

The treatment of 2,4,5,6-tetrachloropyrimidine (I) with NH₃, aliphatic, and aromatic amines resulted almost exclusively in reaction of the 4-Cl atom. The kinetics of the reaction of 2,5,6-trichloro-4-pyrimidylamino derivatives with NaOEt was studied. The derivatives from primary aromatic amines were found to be weak acids, which explained the relationship between constitution and reactivity satisfactorily. PhNH₂ (9.3 g.) in 50 cc. Me₂CO and 50 cc. H₂O heated at 35-40° with 21.8 g. I while maintaining pH 6-7 by the dropwise addition of 20% aqueous Na₂CO₃, heated briefly to 50°, and cooled to 0-5° yielded 86% 4-anilino-2,5,6-trichloropyrimidine (II), m. 83-4° (ligroine). Similarly were prepared the following 4-substituted-2,5,6-trichloropyrimidines (4-substituent, reaction temperature, and m.p. given): p-ClC₆H₄NH (III), 40-50°, 153° (ligroine); o-MeOC₆H₄NH, 40-50°, 183° (C₆H₆); MePhN (IV), 35-40°, 118° (AcOH); p-MeC₆H₄NH, 35-40°, 111° (ligroine); p-MeOC₆H₄NH (V), 35-40°, 129° (ligroine); o-MeC₆H₄NH, 40-50°, 139° (C₆H₆); o-ClC₆H₄NH, 4050°, 158° (C₆H₆); m-HO₃SC₆H₄NH (VI), 40-50%, – (precipitated with KNO₃ as the K salt); m-HO₂CC₆H₄NH, 40-50°, 246° (AcOH); p-O₂NC₆H₄NMe (VII), 85-90° (in aqueous dioxane), 210° (PhCl); p-HOC₆H₄NH (VIII), 30-40°, 112° (C₆H₆); o-HOC₆H₄NH, 40-50°, 216° (EtOH); p-MeO₂SC₆H₄NH (IX), 40-50°, 225° (PhCl); p-O₂NC₆H₄NH (X), 40-50°, 204° (MePh). II (27.5 g.) in 400 cc. concentrated NH₄OH heated 20 hrs. at 110-20° in an autoclave and cooled gave 2,6-diamino-4-anilino-5-chloropyrimidine (XI), m. 218° (MeOCH₂CH₂OH). XI (4.4 g.) in 150 cc. MeOH containing 4.4 g. NaOAc hydrogenated 3 days at room temperature and low pressure, filtered, neutralized with Na₂CO₃, concentrated, diluted with H₂O, and filtered gave 2,6-diamino-4-anilinopyrimidine, m. 177-8° (EtOH), also obtained from 2,4-diamino-6-chloropyrimidine and PhNH₂. BuNH₂ (7.3 g.) in 125 cc. Me₂CO and 125 cc. H₂O treated during 1 hr. at 30-5° with 21.8 g. I at pH 10-11 and extracted with Et₂O yielded 4-butylamino-2,5,6-trichloropyrimidine (XII), b₁₄ 187-8°, m. 62-5°. Similarly was prepared the 4-Et₂N analog (XIII) of XII, b₈ 174-5°, m. 50-1°; the forerun yielded a small amount of 2-diethylamino-4,5,6-trichloropyrimidine, b₈ 152-3°, m. 768°. I (21.8 g.) in 150 cc. concentrated NH₄OH stirred 2 hrs. at 80° and cooled gave 4-amino-2,5,6-trichloropyrimidine, m. 168° (PhCl). II (27.5 g.) in 100 cc. absolute EtOH treated dropwise with 4.0 g. KOH in 100 cc. EtOH, heated 2 hrs. at 70°, filtered, and cooled gave 4-anilino-2,5-dichloro5-ethoxypyrimidine (XIV), m. 124° (EtOH); the alc. mother liquor gave 4-anilino-5,6-dichloro-2-ethoxypyrimidine (XV), m. 66° (ligroine). 2,4-Dichloropyrimidine (14 g.) in 100 cc. Me₂CO and 100 cc. H₂O treated at 40-50° with 9.3 g. PhNH₂ at pH 6-7, cooled to 0-5°, filtered, the residue recrystallized from PhCl, refluxed 4 hrs. with 1 equivalent KOH in 200 cc. EtOH, diluted with H₂O, and filtered yielded 4-anilino-2-ethoxypyrimidine (XVI), m. 121-2° (ligroine). XV (2.84 g.) in 150 cc. absolute EtOH and 2.2 g. Et₃N hydrogenated 21 hrs. at room temperature over 5 g. Pd-C also yielded XVI. XIV gave similarly 4-anilino-6-ethoxypyrimidine, m. 122-3°. II (27.5 g.) and 4.6 g. Na in 200 cc. absolute EtOH refluxed 3 hrs. gave 4-anilino-5-chloro-2,6-diethoxypyrimidine, m. 131° (EtOH). The appropriate compound (6.23 × 10^-3 moles) in 400 cc. absolute EtOH treated at the desired temperature with 100 cc. 1.25N NaOH and the liberated chloride determined titrimetrically in 20-cc. aliquots gave the ks × 10⁵ values (determined at 30°) for the following compounds: 4-methylphenylamino-2,6-dichloro-1,3,5-triazine, above 1000; 4-methylphenylamino-2-amino-6-chloro-1,3,5-triazine, 17; 4-methylphenylamino-2,6-dichloropyrimidine, 9.3; IV, 310; VII, above 500; XIII, 31. The pK values were determined for the following compounds: VI (Na salt), 11.6; 4-(msulfanilino)-2,6-dichloropyrimidine (Na salt), 13.0; 4-(msulfanilino)-2,6-dichloro-1,3,5-triazine (Na salt), 11.2; 4-(m-sulfanilino)-2-amino-6-chloro-1,3,5-triazine (Na salt), 13.8. The ks × 10⁵ (at 30°), k₃ × 10⁴ (at 70°), and k₄ × 10⁴ (at 70°) values (given in this order) were determined in the usual manner for the following compounds: 2-anilino-4,6-dichloro-1,3,5-triazine, 350, -, -; 2-amino-4-anilino-6-chloro-1,3,5-triazine, 37, -, -; 4-anilino-2,6-dichloropyrimidine, 2.2, 0.38, 0.22; II, 1.3, 1.8, 1.2. The ks × 10⁵ (given) were determined at 70° in the usual manner for the following compounds: II, 41; VIII, 210; o-isomer of VIII, 170; V, 49; o-isomer of V, 180; III, 21; o-isomer of III, 15; IX, 6; X, about 5.M

Helvetica Chimica Acta published new progress about 31401-45-3. 31401-45-3 belongs to pyrimidines, auxiliary class Pyrimidine,Amine, name is N,N-Dimethylpyrimidin-4-amine, and the molecular formula is C6H9N3, Category: pyrimidines.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia