Category: pyrimidines

Paterson, Thomas published the artcileSpecific enzyme inhibitors in vitamin biosynthesis. I. Synthesis of 8-substituted pyrido[2,3-d]pyrimidines, SDS of cas: 36075-35-1, the main research area is pyridopyrimidine uracil crotonaldehyde; riboflavin analog.

Condensation of 6-(substituted amino)uracils with α,β-unsaturated carbonyl compounds gave 8-substituted pyrido[2,3-d]pyrimidones; e.g., 6-[(2-hydroxyethyl)-amino]uracil (I) reacted with MeCH:CHCHO in 20% HCl at room temperature to give 72% 5,6,7,8-tetrahydro-7-methyl-5,8-(1-oxapropano)pyrido[2,3-d]pyrimidine-2,4(1H,3H)-dione, which on heating in Ph2O gave 81% 8-(2-hydroxyethyl)-7-methylpyrido[2,3-d]pyrimidine-2,4(3H,8H)-dione (II; R = H, R1 = Me). Substituted pyrido[2,3-d]pyrimidones were also prepared by condensation of 6-(substituted amino)uracils with β-dicarbonyl derivatives; e.g. I with the Na salt of AcCHMeCHO in 85% phosphoric acid gave 47% II (R = Me, R1 = H). PMR studies of II showed that D exchange of protons on C-Me groups at positions 5 and 7 occurred in alk. solution, but protons on a 6-Me group did not exchange; a highly delocalized anionic species was implicated.

Journal of the Chemical Society, Perkin Transactions 17: Organic and Bio-Organic Chemistry published new progress about pyridopyrimidine uracil crotonaldehyde; riboflavin analog. 36075-35-1 belongs to class pyrimidines, name is 7-Methylpyrido[2,3-d]pyrimidine-2,4-diol, and the molecular formula is C8H7N3O2, SDS of cas: 36075-35-1.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Hurst, Derek T. published the artcileThe synthesis of some halopyrimidines and some routes to cyanopyrimidines, Safety of 5-Chloropyrimidine-2-carbonitrile, the main research area is pyrimidine halo cyano; cyanopyrimidine; halopyrimidine.

Pyrimidines substituted with halo or cyano groups were prepared by several methods. E.g., direct bromination of I gave the bromopyrimidinol II, which with POCl3 gave bromochloropyrimidine III. Chloropyrimidine IV was converted into the cyano derivative V by heating with Me3N in benzene and then in a melt of KCN in AcNH2.

Heterocycles published new progress about pyrimidine halo cyano; cyanopyrimidine; halopyrimidine. 38275-56-8 belongs to class pyrimidines, name is 5-Chloropyrimidine-2-carbonitrile, and the molecular formula is C5H2ClN3, Safety of 5-Chloropyrimidine-2-carbonitrile.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Roth, Barbara published the artcile2,4-Diamino-5-benzylpyrimidines as antibacterial agents. 4. 6-Substituted trimethoprim derivatives from phenolic Mannich intermediates. Application to the synthesis of trimethoprim and 3,5-dialkylbenzyl analogs, Product Details of C7H10ClN3, the main research area is pyrimidinediamine benzyl preparation bactericide; bactericide benzylpyrimidinediamine; dihydrofolate reductase benzylpyrimidinediamine; trimethoprim derivative benzylpyrimidinediamine.

The preparation of a wide variety of 6-substituted trimethoprim analogs was readily accomplished by the reaction of 6-substituted 2,4-diaminopyrimidines with 2,6-dimethoxy-4-[(dimethylamino)methyl]phenol at 120-160°. The less reactive 2,6-dialkyl-4-[(dimethylamino)methyl]phenols reacted successfully with 2,4-diamino-6-(alkylthio)pyrimidines to give 5-substituted benzylpyrimidines. The phenolic groups of the products were alkylated in high yield when a nonreactive 6-substituent was present in the pyrimidine ring. 6-(Alkylthio) groups were easily removed with Raney Ni. Trimethoprim (I, R = H, R1 = R2 = MeO) was thus obtained in high yield from its 6-(methylthio) counterpart. The 6-substituted trimethoprim analogs all had low activity as inhibitors of Escherichia coli dihydrofolate reductase and as antibacterial agents.

Journal of Medicinal Chemistry published new progress about pyrimidinediamine benzyl preparation bactericide; bactericide benzylpyrimidinediamine; dihydrofolate reductase benzylpyrimidinediamine; trimethoprim derivative benzylpyrimidinediamine. 73576-33-7 belongs to class pyrimidines, name is 4-Chloro-6-isopropylpyrimidin-2-amine, and the molecular formula is C7H10ClN3, Product Details of C7H10ClN3.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Reddy, Ambati V. Raghava published the artcileSynthesis and characterization of impurities in the production process of lopinavir, Quality Control of 192725-50-1, the main research area is lopinavir synthesis impurity; Lopinavir; Related substances; Synthesis and Characterization of impurities.

Lopinavir is an antiretroviral drug used for the inhibition of HIV protease. Four related substances of lopinavir were observed during the manufacturing process of lopinavir in the laboratory and they were identified. The present work describes the origin, synthesis, characterization, and control of these related substances.

Scientia Pharmaceutica published new progress about Impurities. 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, Quality Control of 192725-50-1.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Mizukami, Satoshi published the artcileRelation between pKa (H2O) of 5-substituted 4-amino-2-methylpyrimidines and half neutralization potential and the behavior of the compounds in nonaqueous solvents., Product Details of C8H11N3O2, the main research area is PYRIMIDINE SYSTEM; METHYLPYRIMIDINE SYSTEM; AMINOMETHYLPYRIMIDINE SYSTEM.

The half neutralization point (HNP) values and potentiometric inflections at the end point in potentiometric titrations were determined for 5-substituted 4-amino-2-methylpyrimidines (substituent = H, CH2OH, CH2NH2, CONH2, CO2Et, CO2H, CHO, or CN) in the following nonaqueous solvents: HOAc, HOAc-Me2CO, HOAc-MeCN, MeOH, EtOH, iso-PrOH, iso-PrOH-HOCH2CH2OH, Me2CO, MeCOEt, iso-BuCOMe, and MeCN. The determinations were effectively made in acidic and dipolar aprotic solvents. With some exceptions, there was a linear relation between the HNP values and the pKa (H2O) values, and between the HNP values and the Hammett σm. Deviations from these relations are discussed. Differential titration of a mixture of 5-hydroxy- and 5-formyl-4-amino-2-methylpyrimidines (I) in various solvents indicated that the power of a solvent to differentiate the mixture increased with increasing Hammett values; a dipolar aprotic solvent of low dielec. constant is recommended for titration of a mixture of the bases with HClO4. From the Hammett equation and uv spectra, these pyrimidines exist largely as the amino form in the solvents and in H2O; the true proton acceptor is the 1-position of the ring. Some abnormal results obtained with I and 5-(aminomethyl)-4-amino-2-methylpyrimidines (II) are explained by chem. reactions. II (0.15 g.) dissolved in 100 ml. Me2CO by warming at 40° or by standing 2 days gave 0.18 g.4-amino-5-(isopropylideneiminomethyl)-2-methylpyrimidine (III), leaflets, m. 151-2°. III (0.2 g.) heated 2 hrs. at 100° with 5 ml. 5% gave II.HCl and Me2CO. III (0.5 g.) in 15 ml. tetrahydrofuran treated slowly at room temperature with 0.5 g. LiAlH4, the mixture stirred 1.5 hrs., H2O added slowly to the cold mixture, and the mixture acidified with HCl gave 4-amino-5-(isopropylideneiminomethyl)-2-methyl-pyrimidine di-HCl (IV), decomposing at 284-5° (aqueous alc.). 4-Amino-5-(chloromethyl)-2-methylpyrimidine (1 g.), 3 g. (Me3)2CHNH2, and 20 ml. EtOH heated at 100° in a sealed tube 2 hrs., and the product in EtOH-Et2O treated with HCl gas gave 1.4 g. IV. A mixture of 1 g. I and 30 ml. absolute MeOH containing 4% dry HCl held 3 hrs. at room temperature and then basified with NaOMe gave 0.7 g. I di-Me acetal, m. 108.5-9° (MeOH); I di-Et acetal, m. 66-8°, was similarly prepared

Chemical & Pharmaceutical Bulletin published new progress about Ionization. 5472-46-8 belongs to class pyrimidines, name is Ethyl 4-amino-2-methylpyrimidine-5-carboxylate, and the molecular formula is C8H11N3O2, Product Details of C8H11N3O2.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Hirai, Eizo published the artcileBehavior of 4-amino-5-carboxy-2-methylpyrimidine in aqueous solution, Safety of Ethyl 4-amino-2-methylpyrimidine-5-carboxylate, the main research area is .

cf. CA 64, 17396e. MeI (4 ml.) added to 1 g. 4-amino-5-ethoxycarbonyl-2-methylpyrimidine in 10 ml. Me2CO, the mixture refluxed 1 hr., and the precipitate formed on cooling heated 1 hr. on a steam bath with 10 ml. 5% HI gave 0.6 g. hemihydrate of the 1-methyl betaine of 4-amino-5-carboxy-2-methylpyrimidine, decomposed 226-7° (aqueous alc.). The 1-methyl betaine of 2-aminonicotinic acid, decomposed 269-71°, and the 1-methyl betaine of 2-aminoisonicotinic acid were similarly prepared The basic ionization constants of 2-aminonicotinic acid (I) and 2-aminoisonicotinic acid (II) and of their Me and Et esters and 1-methyl betaines, and of 4-amino-5-carboxy-2-methylpyrimidine (III) and its Et ester and 1-methyl betaine were determined potentiometrically and spectrophotometrically. The basic pKa values of I and II were much lower than those calculated from the Hammett eq. I and II exist largely as zwitterions in H2O. On the basis of the uv absorption spectra of I-III as compared with those of the corresponding Et esters and 1-methyl betaines, I-III exist predominantly as zwitterions in H2O. An evaluation of the equilibrium constants between the zwitterion form and uncharged form in H2O for I and III from the Edsall and Blanchard equation (CA 27, 5233) is in agreement with this conclusion. Ir spectra of I-III in the solid state show that the compounds form an uncharged polymer linked by H bonding between the carboxyl and a nuclear N.

Chemical & Pharmaceutical Bulletin published new progress about Ionization. 5472-46-8 belongs to class pyrimidines, name is Ethyl 4-amino-2-methylpyrimidine-5-carboxylate, and the molecular formula is C8H11N3O2, Safety of Ethyl 4-amino-2-methylpyrimidine-5-carboxylate.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Mizukami, Satoshi published the artcileIonization constants of some 4,5-substituted 2-methylpyrimidines, SDS of cas: 5472-46-8, the main research area is .

An extension of the Hammett’s equation to pyrimidines is attempted. The basic ionization constants of 4,5-substituted 2-methylpyrimidines are determined potentiometrically or spectrophotometrically. The base strengths are proportional to σm (for 5-substituent) and σp (for 4-substituent) values. A method is developed for the use of the Hammett’s equation in the elucidation of the amino-imino tautomerism and the protonation equilibrium of 4-aminopyrimidines.

Journal of Organic Chemistry published new progress about Ionization. 5472-46-8 belongs to class pyrimidines, name is Ethyl 4-amino-2-methylpyrimidine-5-carboxylate, and the molecular formula is C8H11N3O2, SDS of cas: 5472-46-8.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Prakash, Anjanappa published the artcileEfficient indoles and anilines syntheses employing tert-butyl sulfinamide as ammonia surrogate, HPLC of Formula: 38275-56-8, the main research area is aniline sulfinamide tert butyl preparation; aryl halide amination tert butyl sulfinamide palladium catalyst; indole preparation bromophenylethyne cross coupling tert butyl sulfinamide palladium.

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 Amination. 38275-56-8 belongs to class pyrimidines, name is 5-Chloropyrimidine-2-carbonitrile, and the molecular formula is C5H2ClN3, HPLC of Formula: 38275-56-8.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Benneche, Tore published the artcileSelective oxidations and syntheses of α-halomethylthiopyrimidines, Recommanded Product: 5-Chloro-2-(methylthio)pyrimidine, the main research area is pyrimidine halomethylthio preparation oxidation; oxidation selective halomethylthiopyrimidine; sulfide pyrimidinyl selective oxidation; sulfoxide halomethyl pyrimidinyl.

The molybdenum peroxide complex, MoO3.(Me2N)3PO.H2O was a useful reagent for the oxidation of sulfides to sulfones, in particular for the oxidation of a 2-[(iodomethyl)thio]pyrimidine to its sulfone. The α-chloro analog has also prepared by m-ClC6H4C(O)OOH (I) oxidation α-Halo sulfoxides were prepared selectively by I oxidations Synthesis of the α-halo sulfides are described.

Chemica Scripta published new progress about Oxidation. 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

Foldenyi, R. published the artcileSelectivity in oxidation reactions of methylthio-substituted pyrimidines and triazines, Formula: C5H5ClN2S, the main research area is methylthiopyrimidine oxidation; pyrimidine methylthio oxidation; triazine methylthio oxidation.

It was found during the oxidation of methylthio-substituted pyrimidines and 1,3,5-triazines that pyrimidinesulfones were obtained in better yield than triazinesulfones because the oxidation is influenced by the structure and substitution of the heterocycles and it could not be selectively stopped at this level. Depending on pH and solvent, the methylsulfonyl and the formed methylsulfonium groups can rapidly take part in nucleophilic substitution reactions resulting in hydroxylated and methoxylated triazines and pyrimidines. These reactions may be utilized in such processes where the methylthio substituted heterocycles are formed as byproducts. After oxidation, the nucleophilic substitution leads to the desired products.

Hungarian Journal of Industrial Chemistry published new progress about Oxidation. 38275-42-2 belongs to class pyrimidines, name is 5-Chloro-2-(methylthio)pyrimidine, and the molecular formula is C5H5ClN2S, Formula: C5H5ClN2S.

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia