Oxazolo pyrimidines synthesis

Oxazolone derivatives, photodimerization in solid state 86UK1282. Oxazolo [5,4-d] pyrimidines, synthesis and properties 86AKZ211. Silyloxyoxazoles in organic synthesis 83YGK718. 

Oxazolo[5,4-d]pyrimidines, synthesis and reactivity of 86AKZ211. Perimidines (naphtho[l,8-general review 81 UK 1559. Pyrido[l,2-fl]pyrimidines, chemistry of 83AHC(33)241. 

Design and synthesis of oxazolo pyrimidine based library target kinase... 

H,4H-Oxazolo[5,4,3-y]pyrido[3,2-g]quinolin-4-one, 8-hydroxymethyl-6-methyl — see Nybomyein 5H-Oxazolo[2,3-[Pg.731]

N-Alkylation in the azine ring is demonstrated by the preparation of 2-substituted 6-(jS-D-ribofuranosyl)oxazolo[5,4-rf]pyrimidin-7(6/T)-ones (181). In this case the silyl ether variant of the Hilbert-Johnson method for the synthesis of pyrimidine nucleosides has been used the pyrimidinone (180) is converted into its silyl ether using HMDS and the ether reacted with 2,3,5-tri-O-acetyl-D-ribofuranosyl bromide under Hg(II) catalysis. Deacetylation using methanolic ammonia gives the nucleoside with a /3-anomeric configuration (74JMC1282). 

Azole approach. A one-pot synthesis of substituted 2,3-dihydro-5-oxo-5H-oxazolo[2,3-b ]quinazolines (273) consists of reacting esters of anthranilic acid with a 2-chloro- or 2-bromoalkyl-isocyanate the initially formed urea (271) is cyclized to the acid salt of the oxazoline (272), which on addition of piperidine as base forms the pyrimidine ring (76S469). In a similar reaction the aziridinyl urea (274), which is available from aziridinyl isocyanate... 

Monocyclic and Bicyclic aromatic heterocycles such as imidazoles, thiazoles, thiadiazoles, oxazoles, oxadiazoles quinazolines, indoles, benzimidazoles, purines pyrido[43-d]pyri-midines, thiazolo[5,4-d]pyrimidines, thiazolo[4,5-d]pyrimidines, oxazolo[5,4-d]pyrimi-dines and thieno[2,3-d]pyrimidines are renowned pharmacophores in drug discovery. These special structures are well explained and exemplified in chemical compound libraries. In this chapter, several types of thiazole based heterocyclic scaffolds such as mono-cyclic or bicyclic systems synthesis and their biological activities studies are presented, which are not frequently present in books and reviews. We mention the first importance of synthetic route of various thiazole based compounds and their applications in medicinal chemistry in this chapter. 

Synthesis of Heterocyclic Compounds. Thionyl chloride and pyridine at elevated temperatures convert diarylalkenes, styrenes, and cinnamic acids to benzo[i>]thiophenes and adipic acid to 2,5-bis(chlorocarbonyl)thiophene. Additional heterocycles which have been prepared include thiazolo[3,2-a]indol-3(2//)-ones, oxazolo[5,4- /]pyrimidines, and 1,2,3-thiadiazoles. Treatment of 1,2-diamino aromatic compounds with thionyl chloride gives good yields of fused 1,2,5-thiadiazoles. ... 

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