Recent synthesis of thietanes

• Jiaxi Xu

Beilstein J. Org. Chem. 2020, 16, 1357–1410, doi:10.3762/bjoc.16.116

Thermophilic phosphoribosyltransferases Thermus thermophilus HB27 in nucleotide synthesis

• Ilja V. Fateev,
• Ekaterina V. Sinitsina,
• Aiguzel U. Bikanasova,
• Maria A. Kostromina,
• Elena S. Tuzova,
• Larisa V. Esipova,
• Tatiana I. Muravyova,
• Alexei L. Kayushin,
• Irina D. Konstantinova and
• Roman S. Esipov

Beilstein J. Org. Chem. 2018, 14, 3098–3105, doi:10.3762/bjoc.14.289

• parameters for TthHPRT with natural substrates were determined. Two nucleotides were synthesized: 9-(β-D-ribofuranosyl)-2-chloroadenine 5'-monophosphate (2-Сl-AMP) using TthAPRT and 1-(β-D-ribofuranosyl)pyrazolo[3,4-d]pyrimidine-4-one 5'-monophosphate (Allop-MP) using TthНPRT. Keywords: adenine

• use of hypoxanthine and adenine transferases in multi-enzyme cascades significantly extends the spectrum of synthetic purine nucleotides. Two nucleotides were synthesized: 9-(β-D-ribofuranosyl)-2-chloroadenine 5'-monophosphate (2-Сl-AMP) using TthAPRT and 1-(β-D-ribofuranosyl)pyrazolo[3,4-d]pyrimidine

• (N7), 171.3 (N9), 86.84 (NH2) ppm. 1-(β-D-Ribofuranosyl)pyrazolo[3,4-d]pyrimidine-4-one 5'-monophosphate (Allop-MP): Allopurinol (14 mg, 0.10 mmol) was dissolved in water (203 mL) under stirring and heating at 90 °C, and after cooling to 50 °C, magnesium chloride hexahydrate (41 mg, 0.21 mmol) and

5-Aminopyrazole as precursor in design and synthesis of fused pyrazoloazines

• Ranjana Aggarwal and
• Suresh Kumar

Beilstein J. Org. Chem. 2018, 14, 203–242, doi:10.3762/bjoc.14.15

• -carboxylate (126) with benzoylisothiocyanate or phenylisothiocyantes for the synthesis of N-thiocarbamoyl pyrazole derivatives 180 and 183 which gave pyrazolo[3,4-d]pyrimidine derivatives 181 and 184 on treatment with ethanolic sodium ethoxide. Pyrazolo[3,4-d]pyrimidine derivatives 181 were also obtained

• -Moghazy et al. [129] described the synthesis of pyrazolo[3,4-d]pyrimidine derivatives 187 using a similar approach by the reaction of ethyl 5-amino-1-phenyl-1H-pyrazolo-4-carboxylate (186) and phenyl isothiocyanate in pyridine. The pyrazolo[3,4-d]pyrimidine derivative 187 thus obtained was methylated with

• aldehydes, benzoyl chloride and ethyl acetoacetate to append hydrazone, carbohydrazide and pyrazolone type moieties on pyrazolo[3,4-d]pyrimidine. Further, hydrazinyl derivative 189 provided various fused triazolylpyrazolo[3,4-d]pyrimidines on treatment with various reagents like aliphatic acids, benzoyl

A convenient four-component one-pot strategy toward the synthesis of pyrazolo[3,4-d]pyrimidines

• Mingxing Liu,
• Jiarong Li,
• Hongxin Chai,
• Kai Zhang,
• Deli Yang,
• Qi Zhang and
• Daxin Shi

Beilstein J. Org. Chem. 2015, 11, 2125–2131, doi:10.3762/bjoc.11.229

• Mingxing Liu Jiarong Li Hongxin Chai Kai Zhang Deli Yang Qi Zhang Daxin Shi School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081, China 10.3762/bjoc.11.229 Abstract An efficient one-pot synthesis of pyrazolo[3,4-d]pyrimidine derivatives by the four

• -6-(2-nitrophenyl)-1-phenyl-1H-pyrazolo[3,4-d]pyrimidine was determined by single crystal X-ray diffraction. Keywords: four-component; one-pot; pyrazolo[3,4-d]pyrimidine; sodium alkoxide; Introduction Heterocycles containing a pyrimidine ring are extensively present in natural products and are very

• catalyst (Table 1, entries 1 and 2). Sodium hydroxide could catalyze this reaction, but pyrazolo[3,4-d]pyrimidinone 5aa was obtained instead of pyrazolo[3,4-d]pyrimidine 5a (Table 1, entry 3). This shows that the catalytic properties of sodium hydroxide have some limitations. Fortunately, some strong bases

IBD-mediated oxidative cyclization of pyrimidinylhydrazones and concurrent Dimroth rearrangement: Synthesis of [1,2,4]triazolo[1,5-c]pyrimidine derivatives

• Caifei Tang,
• Zhiming Li and
• Quanrui Wang

Beilstein J. Org. Chem. 2013, 9, 2629–2634, doi:10.3762/bjoc.9.298

• ]pyrimidine derivative, ruxolitinib (INCB018424), was discovered as a selective JAK1 and JAK2 inhibitor, which is currently under clinical investigation [4]. To date, a number of fused pyrimidine-type compounds have been successfully commercialized, such as the pyrazolo[3,4-d]pyrimidine allopurinol and the

Dipyrazolo[1,5-a:4',3'-c]pyridines – a new heterocyclic system accessed via multicomponent reaction

• Wolfgang Holzer,
• Gytė Vilkauskaitė,
• Eglė Arbačiauskienė and
• Algirdas Šačkus

Beilstein J. Org. Chem. 2012, 8, 2223–2229, doi:10.3762/bjoc.8.251

• ]pyrimidine) [4], and Zolazepam (a pyrazolo[3,4-e][1,4]diazepine derivative, used in veterinary medicine) [5]. Particularly pyrazolopyrimidines are a very frequently accessed class of compounds [6] with the particular importance of the pyrazolo[3,4-d]pyrimidine core, which can closely mimic the purine system

One-pot synthesis of novel 1H-pyrimido[4,5-c][1,2]diazepines and pyrazolo[3,4-d]pyrimidines

• Dipak Prajapati,
• Partha P. Baruah,
• Baikuntha J. Gogoi and
• Jagir S. Sandhu

Beilstein J. Org. Chem. 2006, 2, No. 5, doi:10.1186/1860-5397-2-5

• heteroannulation of uracils usually require either forcing conditions[16][17] or relatively longer synthetic pathways.[18] Also, pyrazolo [3,4-d]pyrimidines are a class of naturally occurring fused uracils that possess a wide range of biological activity.[19] Allopurinol (6-dehydroxy-pyrazolo [3,4-d]pyrimidine

• , we have isolated the corresponding 2,4-dioxo-pyrazolo [3,4-d]pyrimidine 6a in 80% yield instead of the expected seven-membered pyrimido[1,2]diazepine 7 or any other product (Scheme 3). The structure of the product 6a thus obtained was confirmed unambiguously by high resolution spectral techniques. To

• examine further the scope of the heteroannulation reaction, 4-phenyl-3-butyn-2-one was treated with 1,3-dimethyl-6-hydrazinouracil 1 in refluxing ethanol for 4 h and the corresponding pyrazolo [3,4-d]pyrimidine derivative was isolated in 78% yield. It is notable that pyrimido[1,2]diazepine on heating in