Month: November 2022

Zhao, Mengmeng published the artcileIdentification, synthesis and characterization of avanafil process impurities and determination by UPLC, HPLC of Formula: 211230-35-2, the main research area is avanafil process UPLC determination characterization.

Avanafil is a phosphodiesterase type 5 inhibitor which is used to treat erectile dysfunction in men. The process-related impurities of avanafil were investigated, and four kinds of impurities in several laboratory batches with a content of 0.29-1.63% were detected by the newly developed gradient ultra-high performance liquid chromatog. (UPLC). Based on the synthesis route and UPLC-MS research, the impurities are inferred as Imp-A, Imp-B, Imp-C and Imp-D. The structures of the impurities were inferred from LC-MS studies and confirmed by synthesis, followed by spectroscopic characterization such as NMR and mass spectrometry. Especially, the synthesis of Imp-D is firstly reported. The drug-related substances can be separated well by efficient and selective ultra-high performance liquid chromatog. on a Waters ACQUITY HSS C18 (50 x 2.1 mm, particle size 1.8μm) column at 35°C, with the mobile phase consisting of ammonium formate (20 mM) and acetonitrile, and the detection at 239 nm with a DAD detector. The method was validated in terms of specificity, linearity, precision, accuracy and sensitivity, and satisfactory results were obtained. The results indicated this developed UPLC method for avanafil and the proposed synthesis mechanism can be used for quality control purposes as required by regulatory agencies to ensure the safety and efficacy of the product.

RSC Advances published new progress about Erectile dysfunction. 211230-35-2 belongs to class pyrimidines, name is Ethyl 4-((4-methoxybenzyl)amino)-2-(methylthio)pyrimidine-5-carboxylate, and the molecular formula is C16H19N3O3S, HPLC of Formula: 211230-35-2.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Shiragami, Makoto published the artcileFormation of diastereomers of 5,6-dihydrothymine-6-sulfonate by deamination of 5-methylcytosine with bisulfite, Safety of 5-Methylcytosinehydrochloride, the main research area is methylcytosine bisulfite deamination stereo; thymine methylcytosine deamination; cytosine bisulfite deamination kinetics.

The bisulfite-mediated deamination of 5-methylcytosine yielded a diastereomeric mixture of 5,6-dihydrothymine-6-sulfonate. One of the diastereomers was identical with the thymine-bisulfite adduct formed by treatment of thymine with bisulfite, and was assigned the structure in which the H at pos. 5 and the sulfonate at pos. 6 are trans. The rates of degradation of this adduct was stable at pH 6.9, the half life being 13 hr at 37°, whereas at pH 8.9 it degrades with a half life of 70 min. The other diastereomer, in which the 5-H and 6-SO3- are cis was stable in mildly alk. conditions. This isomer rapidly generated thymine at pH 13.8.

Chemical & Pharmaceutical Bulletin published new progress about Deamination kinetics. 58366-64-6 belongs to class pyrimidines, name is 5-Methylcytosinehydrochloride, and the molecular formula is C5H8ClN3O, Safety of 5-Methylcytosinehydrochloride.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Basnak, Ivan published the artcileNucleic acid components and their analogs. CXCVIII. Synthesis of uracils substituted in the position 5 or 5,6 with alkyl or cycloalkyl groups and their UV spectra, Application In Synthesis of 19030-75-2, the main research area is thiouracil oxidation; uracil cycloalkyl; Claisen condensation formate acetate; catalyst Claisen condensation; cyclization oxoalkanoate thiourea.

Li diazopropylamide, used as a base in the Claisen condensation of alkylacetates and cycloalkylacetates with EtO2CH or EtOAc gave higher yields of β-oxo esters than NaH or NaN(SiMe2)2. Cyclization of the obtained β-oxo esters with thiourea in an alk. medium gave thiouracils I (X = S), which on subsequent reaction with ClCH2CO2H were transformed into uracils I (X = O, R1 = Me, Me2CH, cyclopropyl, cyclobutyl, cyclopentyl, Pr, Me3C; R2 = Me, Me2CH, Me2CHCH2, cyclopropylmethyl, cyclopropyl).

Collection of Czechoslovak Chemical Communications published new progress about Claisen condensation. 19030-75-2 belongs to class pyrimidines, name is 5-N-Propyluracil, and the molecular formula is C7H10N2O2, Application In Synthesis of 19030-75-2.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Riadi, Yassine published the artcileMicrowave Irradiation-Mediated Synthesis of New Substituted Pyridopyrimidines via the Suzuki-Miyaura Coupling Reaction and Biological Evaluation, Safety of Ethyl 5-bromo-2-(methylthio)pyrimidine-4-carboxylate, the main research area is pyridopyrimidine preparation antibacterial.

An eco-friendly, effective and easy route to synthesize substituted pyridopyrimidines I [Ar = Ph, 3-MeC6H4, 4-pyridyl, etc.] was reported starting from 4-methylsulfanylpyrido[3,2-d]pyrimidines that undergo a SuzukiMiyaura coupling reaction under microwave irradiation Initially, the chlorinated intermediate was prepared from the available chem. reagents. The prepared compounds were effectively synthesized by reacting the chlorinated intermediate with versatile boronic acids. The resulting products were tested for their antimicrobial efficiency against different microbes. In this way, three synthesized derivatives were found to be active against the studied bacterial strains. Unfortunately, the derivatives were found to be inactive against the studied fungus.

Polycyclic Aromatic Compounds published new progress about Antibacterial agents. 74840-38-3 belongs to class pyrimidines, name is Ethyl 5-bromo-2-(methylthio)pyrimidine-4-carboxylate, and the molecular formula is C8H9BrN2O2S, Safety of Ethyl 5-bromo-2-(methylthio)pyrimidine-4-carboxylate.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Venkat Ragavan, R. published the artcileSimple, fast and efficient synthesis of β-keto esters from the esters of heteroaryl compounds, its antimicrobial study and cytotoxicity towards various cancer cell lines, Safety of Ethyl pyrimidine-2-carboxylate, the main research area is heteroaryl keto ester preparation antimicrobial anticancer activity.

A series of β-keto esters were synthesized from heteroaryl esters and Et acetate using LiHMDS as base at -50 to -30 °C. Increases in yields of cross-condensed products were observed and the percentage of self-condensed product was reduced drastically by applying the suitable base (LiHMDS), solvent, and a min. amount of Et acetate. All these β-keto esters were characterized using 1H NMR, 13C NMR and mass spectral data. A plausible mechanism is also depicted to prove the formation of trans-esterified products. All the synthesized compounds were tested for their cytotoxicity towards various cancer cell lines and also tested for their antimicrobial activity towards various bacterial and fungal strains and some of them were found to have promising activity.

Bioorganic & Medicinal Chemistry Letters published new progress about Antibacterial agents. 42839-08-7 belongs to class pyrimidines, name is Ethyl pyrimidine-2-carboxylate, and the molecular formula is C7H8N2O2, Safety of Ethyl pyrimidine-2-carboxylate.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Budesinsky, Zdenek published the artcileNucleophilic substitutions in the 2-methane sulfonylpyrimidine series, Computed Properties of 38275-56-8, the main research area is pyrimidine methanesulfonyl methoxide; methoxy cyano pyrimidine; sweet taste pyrimidine; oxidation methylthiopyrimidine.

Oxidation of 5-substituted 2-methylthiopyrimidines gave the 2-methylsulfonyl derivatives, the nucleophilic substitution of which with NaOMe, N2H4, PhCH2NH2, NaCN, NaSH, and NaCH(CN)CO2Me gave the appropriate 5-substituted 2-methoxy-, 2-mercapto-, 2-hydrazino, 2-benzylamino-, 2-cyano-, and 2-(methoxycarbonylcyano-methyl)pyrimidine. 2-Methylsulfonyl-5-fluoropyrimidine (I) treated at 0° with NaOMe gave 2-methoxy-5-fluoropyrimidine but at a higher temperature and with excess NaOMe, 2,5-dimethoxypyrimidine was formed. I and N2H4 gave 5-hydrazino-2-meth-ylsulfonylpyrimidine. 5-Benzylamino-2-methylsulfonylpyri-midine was prepared analogously. At 10-20°, the reaction of 2 methylsulfonyl-5-halo(fluoro, chloro, bromo)pyrimidines with-NaCN gave the 2-cyano derivatives but at a higher temperature, 2-cyano-5-methylsulfonylpyrimidine was formed. 2-Cyano-5-methylpyrimidine, 2-cyano-5-methoxypyrimidine, 2-cyano-5-fluoropyrimidine, 2-cyano-5-chloropyrimidine, and 2-cyano-5-bromopyrimidine exhibited an intensive sweet taste.

Collection of Czechoslovak Chemical Communications published new progress about Substitution reaction. 38275-56-8 belongs to class pyrimidines, name is 5-Chloropyrimidine-2-carbonitrile, and the molecular formula is C5H2ClN3, Computed Properties of 38275-56-8.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Budesinsky, Zdenek published the artcileNucleophilic substitutions in the 2-methane sulfonylpyrimidine series, Recommanded Product: 5-Chloro-2-(methylthio)pyrimidine, the main research area is pyrimidine methanesulfonyl methoxide; methoxy cyano pyrimidine; sweet taste pyrimidine; oxidation methylthiopyrimidine.

Oxidation of 5-substituted 2-methylthiopyrimidines gave the 2-methylsulfonyl derivatives, the nucleophilic substitution of which with NaOMe, N2H4, PhCH2NH2, NaCN, NaSH, and NaCH(CN)CO2Me gave the appropriate 5-substituted 2-methoxy-, 2-mercapto-, 2-hydrazino, 2-benzylamino-, 2-cyano-, and 2-(methoxycarbonylcyano-methyl)pyrimidine. 2-Methylsulfonyl-5-fluoropyrimidine (I) treated at 0° with NaOMe gave 2-methoxy-5-fluoropyrimidine but at a higher temperature and with excess NaOMe, 2,5-dimethoxypyrimidine was formed. I and N2H4 gave 5-hydrazino-2-meth-ylsulfonylpyrimidine. 5-Benzylamino-2-methylsulfonylpyri-midine was prepared analogously. At 10-20°, the reaction of 2 methylsulfonyl-5-halo(fluoro, chloro, bromo)pyrimidines with-NaCN gave the 2-cyano derivatives but at a higher temperature, 2-cyano-5-methylsulfonylpyrimidine was formed. 2-Cyano-5-methylpyrimidine, 2-cyano-5-methoxypyrimidine, 2-cyano-5-fluoropyrimidine, 2-cyano-5-chloropyrimidine, and 2-cyano-5-bromopyrimidine exhibited an intensive sweet taste.

Collection of Czechoslovak Chemical Communications published new progress about Substitution reaction. 38275-42-2 belongs to class pyrimidines, name is 5-Chloro-2-(methylthio)pyrimidine, and the molecular formula is C5H5ClN2S, Recommanded Product: 5-Chloro-2-(methylthio)pyrimidine.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Strop, P. published the artcileSeparation of alkyl derivatives of uracil by solvophobic adsorption chromatography on Spheron, Safety of 5-N-Propyluracil, the main research area is uracil derivative chromatog; pyrimidine derivative chromatog.

Derivatives of such related substances as cytosine, uracil, thymine, 6-methyluracil, 5-ethyluracil, 5-propyluracil, 5-isopropyluracil, 5-cyclopropyluracil, 5-allyluracil, 5,6-trimethyleneuracil, 6-cyclopropyluracil, 5-cyclobutyluracil and 5-tert-butyluracil were separated on a column of Spheron P-300. Retention on the column was found to depend on the size of the nonpolar part of the mol. The chromatog. behavior was analyzed according to the theory of solvophobic chromatog.

Journal of Chromatography published new progress about Liquid chromatography. 19030-75-2 belongs to class pyrimidines, name is 5-N-Propyluracil, and the molecular formula is C7H10N2O2, Safety of 5-N-Propyluracil.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Raju, I. V. Soma published the artcileA stability indicating LC method for lopinavir, Safety of (S)-3-Methyl-2-(2-oxotetrahydropyrimidin-1(2H)-yl)butanoic acid, the main research area is lopinavir determination reverse phase liquid chromatog.

An isocratic reverse phase liquid chromatog. (RP-LC) assay method was developed for the quant. determination of lopinavir in bulk drug and in pharmaceutical dosage form, used to treat antiviral. The developed method is also applicable for the related substances determination The chromatog. separation was achieved on Agilent Zorbax SB-C18 250 × 4.6 mm, 5 μm. The LC method employs solution A as mobile phase. The solution A contains a mixture of phosphate buffer pH 4.0: acetonitrile (55:45, volume/volume). The flow rate was 1.5 mL/min-1 and the detection wavelength was 210 nm. In the developed HPLC method the resolution between lopinavir and its potential impurities Imp-1, Imp-2, Imp-3, and Imp-4 is >10.0. The drug was subjected to stress conditions of hydrolysis, oxidation, photolysis, and thermal degradation Considerable degradation occurs in thermal, UV, acid medium, and oxidative stress conditions. The stress samples were assayed against a qualified reference standard and the mass balance was found close to 99.7%. The developed RP-LC method was validated with respect to linearity, accuracy, precision, and robustness.

Analytical Chemistry: An Indian Journal published new progress about Drug delivery systems. 192725-50-1 belongs to class pyrimidines, name is (S)-3-Methyl-2-(2-oxotetrahydropyrimidin-1(2H)-yl)butanoic acid, and the molecular formula is C9H16N2O3, Safety of (S)-3-Methyl-2-(2-oxotetrahydropyrimidin-1(2H)-yl)butanoic acid.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

White, James D. published the artcileAsymmetric Synthesis of Epicylindrospermopsin via Intramolecular Nitrone Cycloaddition. Assignment of Absolute Configuration, SDS of cas: 36847-11-7, the main research area is epicylindrospermopsin asym synthesis absolute configuration; cycloaddition nitrone asym synthesis epicylindrospermopsin; crystal mol structure methoxypyrimidinyl hydroxypiperidinopyrimidinone.

A synthesis of (-)-epicylindrospermopsin (I) was completed that establishes its absolute configuration and corroborates the corrected structural assignment previously made to this toxin by Weinreb et al. The hydroxylamine (3S,4S)-4-BrC6H4CH2OCH2CH(NHOH)CHMeCH:CH2, prepared from 4-bromobenzyloxyacetaldehyde, was condensed with aldehyde II, obtained in nine steps from (R)-methionine, to give nitrone III. Intramol. cycloaddition of III proceeded stereoselectively to yield an oxazabicyclo[2.2.1]heptane, which after reduction and deprotection afforded an hydroxy piperidine derivative The latter was transformed via its cyclic urea to the inverted C12 alc., and the derived azide was cyclized to produce the guanidine moiety of IV. Final sulfation of the C12 hydroxyl group furnished (-)-I. An x-ray anal. of a crystalline diol intermediate determined the relative stereostructure.

Journal of the American Chemical Society published new progress about Absolute configuration. 36847-11-7 belongs to class pyrimidines, name is 2,4,6-Tribromopyrimidine, and the molecular formula is C4HBr3N2, SDS of cas: 36847-11-7.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia