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Thiazolo pyrimidines 2.3- dihydro

Reaction of 2-aminothiazole with ethyl acrylate yields 5.6-dihydro-7H-thiazolo[3,2a]pyrimidin-7-one (116) (Scheme 78) (169). [Pg.54]

Refluxing, 5.6-dihydro-7H-thiazolo[3,2-a]pyrimidine-7-one (370j with isopropylamine led to 2-imino-3-[2-(isopropylaminocarbonyl)ethyl]-thiazoline (371) (108). Similarly. tetrahydrobenzothiazolo[3,2-fl][2.3-f>]-quinazoline is opened by potassium hydroxide, yielding 373 (Scheme 214)... [Pg.123]

Thiazolo[3,2-c]pyrimidinium, anhydro-8-ethoxy-2,3-dihydro-5-methyl- H NMR, 6, 676 (69ACS2437) 5H-Thiazolo[3,2-a]pyrimidin-5-one IR, 6. 681 (71JCS(C)2094)... [Pg.67]

A general scheme, which constructs the thiazolo variety of various bridgehead heterocycles, is basically an extension of HTIB-mediated modification of Hantzsch thiazole synthesis (Scheme 51). Thus, synthesis of 3-substituted-5,6-dihydro-4//-imidazo[2,l-b]thiazoles 202 has been achieved by the treatment of a-tosyloxyacetophenones (generated by the oxidation of 51 with HTIB) with ethylenethiourea [92JCS(P1)707], The method is successfully extended to synthesize 4,5,6,7-tetrahydrothiazolo[3,2-a]pyrimidines 203... [Pg.46]

The one-step synthesis of further tri- and tetracyclic pteridine derivatives from 2-aminopyrazine 153 has also been described <2001JHC1173>. Cyclic analogues of A -[bis(methylthio)methylene]amino reagents such as 2-(methylthio)-2-thiazoline, 5,6-dihydro-2-(methylthio)-4//-l,3-thiazine, 2-(methylthio)-2-imidazoline, 2-(methylthio)-l,4,5,6-tetrahydro-pyrimidine, 2-(methylthio)-2-pyrazine, and 2-chloropyrimidine reacted with aminopyrazine 153 to afford thiazolo/thia-zino[2,3-3]- 159 ( = 1 (53%), n = 2 (42%)), imidazo/pyrimidino[2,l-/ ]- 160 ( = 1 (53%), = 2 (57%)), pyrazino[2,l-/ ]-161 (21%), and pyrimido[2,l-/ ]-pteridine 162 (42%) derivatives, respectively. [Pg.945]

UV, 6, 680 (71JCS(C)1527> 7H-Thiazolo[3,2-a]pyrimidin-7-one, 5-methyl-IR, 6, 681 (7UCS(C)2094> Thiazolo[3,2-e]pyrimidm-7-one, 2,3-dihydro-5-phenyl-... [Pg.67]

Three methods were reported to obtain the title compounds. The first was based on a reaction sequence starting from 5,6-diamino-4-thiouracil-sodium salt, alkylation with 1,2-dibromoethane to 7,8-diamino-2,3-dihydro-5//-thiazolo-[3,2-c]pyrimidine (135) and fusion with urea or thiourea under formation of a third ring to the respective 7,8-dihydrothiazolo[2,3-/]purine-2,5(l//,3//)-dione (136) and 2,3,7,8-tetrahydro-2-thioxothiazolo[2,3- ]purin-5(l//)-one (137) (92FES1315) (Scheme 37). [Pg.105]

Other Condensed Systems incorporating Thiazole. - Dihydro- and tetrahydro-cyclopropa[c ] thiazole derivatives, cyclenothiazoles, hexahydrocyclo-octa[rf] thiazolo [3,2-a] pyrimidines, 2-amino-10,l 1 -dihydrophenanthro-... [Pg.190]

See other pages where Thiazolo pyrimidines 2.3- dihydro is mentioned: [Pg.67]    [Pg.67]    [Pg.67]    [Pg.877]    [Pg.877]    [Pg.878]    [Pg.257]    [Pg.67]    [Pg.67]    [Pg.67]    [Pg.877]    [Pg.877]    [Pg.878]    [Pg.243]    [Pg.353]    [Pg.235]    [Pg.353]    [Pg.362]    [Pg.359]    [Pg.361]    [Pg.67]    [Pg.67]    [Pg.877]    [Pg.877]    [Pg.878]    [Pg.95]    [Pg.186]    [Pg.310]    [Pg.312]    [Pg.312]    [Pg.316]    [Pg.67]    [Pg.67]    [Pg.67]   
See also in sourсe #XX -- [ Pg.17 , Pg.670 ]



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1.2- Dihydro-5//-thiazolo

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