- Novel and efficient synthesis of 2-aminooxazoles from pyrimidin-2(1H)-one
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Stepwise conversion of pyrimidin-2(1H)-one to 2-amino-5-aryloxazoles via oxazolo[3,2-a]pyrimidinium salts is reported. The sequence involves, (i) regioselective N-alkylation of pyrimidone by phenacyl bromides, (ii) cyclization of obtained 1-(2-aryl-2-oxoethyl)pyrimidin-2(1H)-ones into oxazolo[3,2-a] pyrimidinium salts under the action of fuming sulfuric (or triflic) acid, and (iii) reaction of the obtained salts with hydrazine leading to 2-amino-5-aryloxazoles. Georg Thieme Verlag Stuttgart.
- Alifanov, Vadim L.,Babaev, Eugene V.
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p. 263 - 270
(2007/10/03)
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- Development of a concise scaleable synthesis of 2-chloro-5-(pyridin-2-yl) pyrimidine via a Negishi cross-coupling
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A practical and scaleable synthesis of 2-chloro-5-(pyridin-2-yl) pyrimidine, an intermediate in the synthesis of a selective PDE-V inhibitor, was developed. A Negishi cross-coupling between the in situ prepared 2-pyridylzinc chloride and 5-iodo-2-chloropyrimidine catalyzed by Pd(PPh3)4 afforded the product in one step. Development of a convenient purification did away with the necessity of chromatography, allowing the preparation of the product on kilogram scale.
- Perez-Balado, Carlos,Willemsens, Albert,Ormerod, Dominic,Aelterman, Wim,Mertens, Narda
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p. 237 - 240
(2012/12/26)
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- O-Alkyl-O-pyrimidin (2)yl-thionophosphonic acid esters
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O-Alkyl-O-pyrimidin(2)yl-thionophosphonic acid esters of the formula STR1 in which R is alkyl with 1 to 6 carbon atoms, R' is alkyl with 1 to 6 carbon atoms or phenyl, R" and RIV each independently is hydrogen or alkyl with 1 to 4 carbon atoms, and R'" is halogen or hydrogen. Which possess insecticidal, acaricidal and nematocidal properties.
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