Results 221 to 230 of about 138,736 (279)

Cyclization of Ketones with Nitriles under Base: A General and Economical Synthesis of Pyrimidines.

Organic Letters, 2018
A facile, general, and economical synthesis of diversely functionalized pyrimidines has been realized under basic conditions via the copper-catalyzed cyclization of ketones with nitriles.
Lebin Su, K. Sun, Neng Pan, Long Liu, Mengli Sun, Jianyu Dong, Yongbo Zhou, S. Yin   +7 more
semanticscholar   +1 more source

Efficient Access to Imidazo[1,2- a]pyridines/pyrazines/pyrimidines via Catalyst-Free Annulation Reaction under Microwave Irradiation in Green Solvent.

ACS Combinatorial Science, 2018
An expeditious catalyst-free heteroannulation reaction for imidazo[1,2- a]pyridines/pyrimidines/pyrazines was developed in green solvent under microwave irradiation.
R. N. Rao, Balamurali Mm, Barnali Maiti, Ranjit Thakuria, K. Chanda   +4 more
semanticscholar   +1 more source

CBr4 Mediated Oxidative C-N Bond Formation: Applied in the Synthesis of Imidazo[1,2-α]pyridines and Imidazo[1,2-α]pyrimidines.

Organic Letters, 2016
The carbon tetrabromide mediated oxidative carbon-nitrogen bond formation of 2-aminopyridines or 2-aminopyrimidines with β-keto esters or 1,3-diones, leading to a variety of complex imidazo[1,2-α]pyridines or imidazo[1,2-α]pyrimidines, is reported.
Congde Huo, Jing Tang, Haisheng Xie, Yajun Wang, Jie Dong   +4 more
semanticscholar   +1 more source

ChemInform Abstract: Synthesis of Novel Carbazoyl‐Linked Pyrimidine—Pyrimidine and Pyrimidine—Purine Dinucleotide Analogues.

ChemInform, 1999
AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Susana Fernández, Vicente Gotor, Miguel Ferrero, Julia Magdalena   +3 more
openaire   +3 more sources

Anticancer pyrimidines, pyrimidine nucleosides and prodrugs

1990
Of the plethora of pyrimidines, pyrimidine nucleosides, analogues and prodrug derivatives that have been synthesised and evaluated as anticancer agents, only two are in general clinical use. The long-studied 5-fluorouracil (5-FUra (1), see Scheme 9.1), and some nucleoside and prodrug derivatives, are used regularly for the treatment of breast cancer ...
M. J. Robins, M. MacCoss
openaire   +2 more sources

I2-Catalyzed Multicomponent Reactions for Accessing Densely Functionalized Pyrazolo[1,5-a]pyrimidines and Their Disulphenylated Derivatives.

Journal of Organic Chemistry, 2016
New I2-catalyzed multicomponent bicyclization reactions of β-ketonitriles with sulfonyl hydrazides have been established, providing a direct and metal-free access toward unreported pyrazolo[1,5-a]pyrimidin-4-ium sulfonates.
Jun Sun, Jiang-Kai Qiu, Bo Jiang, Wen-Juan Hao, Cheng Guo, S. Tu   +5 more
semanticscholar   +1 more source

New Pyrimidine Pathway involved in the Biosynthesis of the Pyrimidine of Thiamine [PDF]

Nature, 1967
OUR, studies with mutants of Salmonella typhimurium LT2 have revealed that the pyrimidine moiety of thiamine is synthesized by a new biosynthetic route using intermediates from the purine biosynthetic pathway. Radioactive labelling has indicated that the conventional nucleic acid pyrimidine biosynthetic pathway is not used for biosynthesis of the ...
Peter C. Newell, R. G. Tucker
openaire   +2 more sources

Cu-Catalyzed [3 + 3] Annulation for the Synthesis of Pyrimidines via β-C(sp3)-H Functionalization of Saturated Ketones.

Journal of Organic Chemistry, 2016
A novel, efficient, and facile approach for the synthesis of structurally important pyrimidines has been successfully developed by Cu-catalyzed and 4-HO-TEMPO-mediated [3 + 3] annulation of commercially available amidines with saturated ketones.
Junchen Zhan, Meng-Wei Wu, Fei Chen, B. Han   +3 more
semanticscholar   +1 more source

Design, Synthesis, and Biological Evaluation of Substituted Pyrimidines as Potential Phosphatidylinositol 3-Kinase (PI3K) Inhibitors.

Journal of Medicinal Chemistry, 2016
Three series of substituted pyrimidines were designed and synthesized. All target compounds were screened for kinase inhibitory activities against PI3Kα, and most IC50 values were found within the nanomolar range. Compounds 5d and 5p displayed comparable
Jiquan Zhang, Yongjie Luo, Yan-Shi Xiong, Yang Yu, Zheng-chao Tu, Zi-Jie Long, Xiao-Ju Lai, Hui-Xuan Chen, Yuan Luo, J. Weng, G. Lu   +10 more
semanticscholar   +1 more source

Pyrimidines as block units in heterocycles: novel synthesis of pyrimidines and condensed pyrimidine derivatives

Journal of the Iranian Chemical Society, 2019
Compound 1 condensed with benzaldehyde to produce styryl pyrimidine 2. Pyridopyrimidines 5, 8 and 10 resulted from [4 + 2] cycloaddition (condensation) of 1 with malononitrile, ethyl cyanoacetate and/or ethyl acetoacetate. Compound 1 was also concerted to pyridopyrimidine 14 through multistep reaction (hydrolysis, chlorination, isothiocyanate formation
Hamed Y. Moustafa, Wesam S. Shehab, Hamdi M. A. Rahman, Mohamed G. Assy, Magda H. Abdellattif   +4 more
openaire   +2 more sources