Benzothieno pyrimidin-4-ones

The tetracyclic systems, triazolothienopyrimidines, tetrazolothienopyrimidines, and related tetrazepino derivatives, were obtained from 2,3,5,6,7,8-hexahydro-3-amino-2-hydrazino-l-benzothieno[2,3-<7]pyrimidine-4(37/)-one <1995PS85>. 

The synthesis of thiazoIo[3,2-a]-[I]benzothieno[2,3-t/]pyrimidin-3(2//)-ones (323) is accomplished in two ways. The first involves direct condensation of thione with a-chloroester, while the second, the cyclization of the acid through a mesoionic compound, is affected as illustrated in Scheme 76 [81IJC(B)538]. 3-MethyI(phenyl)-4-oxo-5,6,7,8-tetrahydro[l]benzothi-eno[2,3-c/]pyrimidine-2-thiones (322a,b) react with ethyl a-chlorophe-... 

A tandem aza-Wittig/heterocumulene-mediated annulation route was developed for the efficient production of 6,7,8,9-tetrahydro-benzothieno[2,3-r/]-l,2,4-triazolo[l,5-a]pyrimidin-10(3F/)-ones <05S1601>, and an amine oxide rearrangement was key to the regioselective preparation of pyrrolo[2,3-J]pyrimidines <0581164>. Hexahydro-2-phenacylidene-pyrimidines gave -lactam fused 8-aroyl-2,3,4,5-tetrahydro-7-hydroxy-6//-pyrrolo[l,2-a]py-rimidine-6-ones when treated with (COCl), in the presence of NaH <05IJH87>, and methyl... 

Synthesis of 3-substituted 6-arylbenzo[r/][l,2,3]triazin-4(3/f)-ones using polymer bound triazenes has been reported <04JCO38>. Gas-phase thermolysis of thieno[3,2-e][l,2,4]triazines yielded benzonitrile, isothiazole, pyrimidine, [ 1 benzothieno[2,3-dJpyrimidine and thieno[3,2-rf thiazole derivatives. These products were separated by HPLC and column chromatography and characterized using GCMS, LCMS, H, C-NMR and 2D NMR spectroscopy... 

The iminophosphoranes (63), that are readily synthesized from 2-chloro-5-cyano-6-ethoxy-4-phenylpyridine-3-carboxaldehyde, were reacted with aromatic isocyanates to obtain directly several new 1,8-naphthyridines in an aza-Wittig/electrocyclic ring-closure process." Phosphazene (64) was reacted with phenyl isocyanate (or 4-chlorophenyl isocyanate) to give a carbodiimide which was cyclized to afford a series of new, 2-substituted 3-aryl-8,9,10,ll-tetrahydro-5-methyl[l]benzothieno[3,2 5,6]-pyrido[4,3-d]pyrimidin-4(3//)-ones." ... 

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