Thieno pyrimidinones

A number of pyrimidines fused to five- or six-membered rings have been degraded to substituted pyrimidines and many of these reactions have been summarized elsewhere <1994HC(52)1>. A recent example used Raney nickel to remove a sulfur atom from the imidazo[4, 5 4,5]thieno[3,2-r/]pyrimidinone 966 <20010L3209, 2002JOC3365>. 

In the antiinfective field, the synthesis and evaluation of pyrimidinone antibiotics with a broader spectrum against Gram-positive bacteria was reported <03BMCL2641>. New pyrimidines <03IJC910, 031JH217>, pyrimidine-incorporated 1,3,4-thiadiazoles <031JH245>, pyrazolo[3,4-ci]pyrimidines <03HAC530>, N-[5-(2-furanyl)-2-methyl-4-oxo-4//-thieno[2,3-... 

Pyrimido[3, 2 4,5]thieno[3,2-(/]pyrimidinones reacted with hydrazonoyl halides in dioxane and triethylamine to give the corresponding tetracyclic fused tetrazines <06JHC935>. 

Modica, M., Santagati, M., Russo, F., Parotti, L., Degioia, L., Selvaggini, C., Salmona, M. and Mennini, T. (1997). [[(Arylpiperazinyl)alkyl]thio]thieno[2,3-d]pyrimidinone Derivatives as High-Affinity, Selective 5-HTla Receptor Ligands. J.Med.Chem.,40,574-585. 

Cycloaddition and cyclization routes were used to access certain 1,3-diazines. The 4+2 cycloaddition reaction of 4-(N-allyl-N-aryl)amino-l,3-diaza-l,3-butadienes with vinyl-, isopropenyl-, and chloroketene led to pyrimidinone-fused pyrimidinones <97T13841>. Cis-cyclopenta[d]pyrimidines were derived from cis-2-amino-l-cyclopentanecarboxylates by cyclization with KOCN and KSCN <97JHC1211>. 2-Thioxopyrido[3, 2 4,5]thieno[3,2-r/]pyrimidin-4(3//)-ones 19 were prepared by cyclocondensation of 2-carbethoxy-3-amino-4-phenyl-6-substituted-thieno[2,3-/)]pyridines and isothiocyanates <97JHC937>. Thiazolyl-benzimidazoles derived from 2-cyanomethyl-l//-benzimidazole and 2,3-dihydrothiazole-2-(3//)-thiones were cyclized to the corresponding thiazolo[4,5-r/]pyrimidines <97PHA346>. Reductive cyclization of 6-cyanomethyl-5-nitropyrimidines afforded 7-alkyl-5//-pyrrolo[3,2-r/]pyrimidines and 6-amino-7,7-dialkyl-7//-pyrrolo[3,2-rf]pyrimidines <97T391>. 7-Methyl-5-alkyl-2-vinyl-pyrazolo[3,4-r/]pyrimidine-4,6(5//,7//)-diones arose from cyclization and alkylation of... 

One of the most common synthetic approaches to the construction of heterocyclic compounds involves the reaction of /3-keto esters with bifunctional nucleophiles. Thus a variety of reactions of (1) with different bifunctional heteronucleophiles, including hydrazine, substituted aminotriazoles, 2-aminopyridines, o-phenylenediamines, and o-aminothiophenol, lead to polynuclear condensed thieno compounds (e.g. 2-8) of potential medicinal interest featuring the pyrazolone, pyrimidinone, benzodiazepine, and benzothiazepine nuclei. Cannabinoid analogs can be prepared through cyclization of the condensation products of (1) with bifunctional oxygenated nucleophiles such as substituted resorcinols. ... 

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