Synthesis and Characterization of Novel Functionally Substituted Planar Pyrimidothienoisoquinolines and Nonplanar (3a, 4, 9a)-pyrazolo[3,4-]isoquinolines.

7-Acetyl-8-aryl-4-cyano-1,6-dimethyl-6-hydroxy-5,6,7,8-tetrahydroisoquinolin-3(2)-thiones , are prepared and dehydrated to give 7-acetyl-8-aryl-4-cyano-1,6-dimethyl-6-hydroxy-7,8-dihydrodroisoquinolin-3(2)-thiones , via a novel method by heating with acetyl chloride in acetic acid. The reaction of both compounds , and , with -aryl-2-chloroacetamides - under two different conditions gave the same corresponding products, 7-acetyl-8-aryl-3-(-aryl)carbamoylmethylsulfanyl-4-cyano-1,6-dimethyl-7,8-dihydroisoquinolines -, in high yields. On treatment of compounds ,, in methanol with a slightly excess molar amount of sodium methoxide, they underwent intramolecular Thorpe-Ziegler cyclization followed by spontaneous aromatization, providing the planar 7-acetyl-1-amino-6-aryl-2-(-aryl)carbamoyl-5,8-dimethyl-8,9-dihydrothieno[2,3-] isoquinolines ,, in good yield. Cyclocondensation reactions of , with phenyl hydrazine, thiosemicarbazide, or hydrazine hydrate led to the formation of nonplanar (3a, 4, 9a)-pyrazolo[3,4-]isoquinolines , , and , respectively. The reaction of compound with 2-chloromethylquinazolin-4(3)-one in the presence of anhydrous sodium acetate gave the expected thienopyrazoloisoquinolone . Heating the latter compound () with triethyl orthoformate in glacial acetic acid afforded the fused heptacyclic compound . All of the synthesized compounds were characterized based on their full spectral analyses such as IR, H nuclear magnetic resonance (NMR), and mass spectrometry (MS). Moreover, the crystal structure of compound was elucidated by X-ray diffraction analysis.