A Convenient Synthesis of 1-Amino-4-methyl-4 H -3-thia-4,5 a ,10-triazacyclopenta[ a ]fluoren-5-ones and Some New 2,3-Dihydro-1,3,4-thiadiazoles.

1-amino-4-methyl-4H-3-thia-4,5a,10-triazacyclopenta-[ a ]fluoren-5-one and 6-methyl-6H-,9H-thia-4b,6,9,11,12-pentaazaindeno[1,2- a ]-fluorene-5,8-dione derivatives were prepared from 2-methyl-1-oxo-3-thioxo-2,4,9 b -trihydropyrimidino[1,6- a ] benzimidazole-4-carbonitrile. Also, 2,3-dihydro-1,3,4-thidazoles were synthesized via a reaction of hydrazonoyl chlorides with 3-(methylamino)-2-substituted 3-thioxopropanenitrile. Structures of newly synthesized compounds were elucidated on the basis of elemental analyses, spectral data, and alternative methods synthesis whenever possible. [ABSTRACT FROM AUTHOR]