1.2.3.6.7.116- Hexahydro-4//-pyrido isoquinolin-4-thione

Reaction of 2-pyridineacetamides 197 with Me2NCH(OMe)2 afforded 3//-pyrido[l,2-f]pyrimidin-3-ones 198 (Equation 42) <1998WO98/027098, 2000USP6147080>. Reaction of l-(2-aminocthyl)-l, 2,3,4-tetrahydroisoquino-lincs with CS2, C(OEt>4, and nitroguanidine gave 1,2,3,6,7,1 1 h-hexahydro-4//-pyrimido[6,l -<2 isoquinoline-4-thiones, 4-ethoxy-1,6,7,1 lb-tetrahydro-2//-pyrimido[6,l -zz isoquinolines, and 4-(nitroimino)-l,2,3,6,7,l lb-hexahydro-... 

Structures of 3-[(4-methylphenyl)amino]-47/-pyrido[l,2-tf]pyrazine-4-thione, iV-tosyl-3-[(4-methylphenyl)a-mino]-4//-pyrido[l,2-tf]pyrazine 4-imine, and 246 were confirmed by X-ray investigations <1999JPR332>. The stereostructures of (4A,llaA)-lla-ethoxycarbonylT,3,4,6,lla-hexahydro-l,3,4,6,ll,lla-hexahydro-4-methox-ycarbonyl-l-oxo-[l,4]oxazino[4,3-A isoquinoline <1995ZK787>, 2//-pyrazino[l,2- ]isoquinolinc-l,4-dione 247 <2001TL543>, 4-benzyl-2-methyl-1,3,4,6,7,11 b-hcxahydro-2//-pyrazino[2,l -zz] isoqu incline-3,6-dione... 

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