- A general and efficient synthesis of 2-substituted oxazolopyridines
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Starting from commercially available halonitropyridines and haloaminopyridines, 2-substituted-oxazolo[5,4-b]pyridines, and 2-aryl-oxazolo[4,5-b]pyridines were synthesized in good yields by using a Cu(I)-mediated cyclization of halopyridylamides as a key step. Georg Thieme Verlag Stuttgart.
- Xu, Dan,Xu, Xianfang,Liu, Zongliang,Sun, Li-Ping,You, Qidong
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scheme or table
p. 1172 - 1174
(2009/08/09)
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- Process for the synthesis of oxazolopyridine compounds
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Process for the synthesis of compounds of formula (I): STR1 their pyridinium salts and N-oxides, in which formula: the nitrogen of the pyridine ring is situated in the α-, β-, γ- or δ-position with respect to the ring junction; R1 represents a halogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkoxy or a nitro, substituted or unsubstituted amino, phenyl or cyano group; 0≤m≤2; R2 represents a lower alkyl or cycloalkyl group, a 5- or 6-membered heterocycle containing 1 or 2 hetero atoms, substituted or otherwise, or an aryl group STR2 such that: R3 represents a halogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkoxy or a nitro, phenyl, substituted or unsubstituted sulfonyl, cyano, thioalkyl, substituted or unsubstituted amino, substituted or unsubstituted sulfinyl, mercapto, hydroxyl or ester group, 0≤n≤5 employing trimethylsilyl polyphosphate (PPSE) as a cyclization agent and enabling the compounds of formula (I) to be obtained in virtually quantitative yields. The compounds of formula I have anti-inflammatory, analgesic, and antipyretic activity.
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- A New Convenient Synthesis of 2-Aryl- and 2-Heteroaryloxazolopyridines
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Several 2-aryl- and 2-heteroaryloxazolopyridines were synthesized in high yields from 3-(arylcarbonylamino)-2-chloropyridines by heating in the presence of trimethylsilylpolyphosphate ester.
- Flouzant, Christine,Guillaumet, Gerald
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- Novel synthesis of 5,11-dihydro-6H-pyrido[2,3-b]-[1,4]-benzodiazepin-6-ones and related studies (1)
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5,11-Dihydro-6H-pyrido[2,3-b][1,4]benzodiazepin-6-one (1), a basic intermediate in the preparation of 11-α-aminoacetyl derivatives with important biological activities, has been obtained by a three-step synthesis starting from easily available isatoic anhydride and anhydro ornithine. Some model cyclisation reactions leading to 5-member ring derivatives 10 and 12 instead of 7-member ring analogues of 1, are reported. Easy transformations of the tetrahydro congener of 1, i.e. compound 4 into 19, which actually represents a tetrahedral intermediate in the transformation of 5 into 4, is noticed. Further rearrangement of 19 into spiro compounds 20, and return of the latter into 5 is described.
- Oklobdzija,Comisso,Decorte,et al.
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p. 1329 - 1334
(2007/10/02)
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