الفهرس Only 14 pages are availabe for public view
 |  | from | 107 |  |  |
| | | from | 107 | | |
Abstract
Treatment of 2-(l-ethoxycarbonyl)benzimidazolylacetonitrile (1) with methyl isothiocyanate (2) in presence of potassium hydroxide followed by acidify with hydrochloric acid gave 4 . Treatment of 4 with chloroacetone in n,n-dimethylformamide containing potassium hydroxide gave 2-acetyl-l-amino-4-methyl-4H-3-thia-4,5a,10-triazacyclopenta[a]fluoren-5-one (6a) Also, 3-chloropentan-2,4-dione reacted with 4 in N,N-dimethylformamide containing potassium hydroxide gave product identical in all respects (mp., mixed mp. and spectra) with 6a Similar, compound 4 reacted with each of tw-bromoacetophenone, ethyl chloroacetate or chloroacetonitrile in n,n -dimethylformamide containing potassium hydroxide to give l-amino-4-methyl-2-subsituted 4H-3-thia-4,5a,10-triazacyclopenta[a]fluoren-5-one 6b-d, respectively. Analogy, compound 4 reacted with ethyl 2-chloro-3-oxobutanoate in presence of potassium hydroxide in n,n-dimethylformamide solution gave product identical in all respects (mp., mixed mp. and spectra) with 6c. Compound 6d reacted with each of formic acid or formamide to give the corresponding 10a and 10b, respectively . Treatment of 4 with iodomethane in presence of potassium hydroxide in n,n-dimethylformamide gave (11). Compound 11 reacted with hydrazine hydrate in boiling ethanol under reflux gave (12) Compound 12 reacted with pentan-2,4-dione in boiling acetic acid under reflux gave (13) . Treatment of 12 with ethyl 3-oxobutanoate in boiling acetic acid under reflux afforded (15). On the other hand, treatment of 12 with acetoacetanilide in boiling acetic acid gave product identical in all respects (mp., mixed mp. and spectra) with 15. Similarly, treatment of 12 with each of ethyl benzoylacetate or benzoylacetanilide in boiling acetic acid under reflux afforded (16). However, treatment of 12 with a-cyanocinamonitrile in boiling ethanol under reflux and presence of catalitically amount of piperdine gave (18) . Thus, treatment of 19, which prepared via reaction of 12 with benzaldehyde in ethanolic piperdine solution with malononitrile in boiling ethanol containing catalitically piperdine, gave 18. Similarly, a-cyanocinnamate reacted with 12 in boiling ethanol under reflux and presence of catalitically amount of piperdine to give (21). Also, compound 19 reacted with ethyl cyanoacetate in boiling ethanol containing catalitically amount of piperdine to give 21 . Next, treatment of 12 with sodium nitrite in hydrochloric acid solution to afford diazonium chloride 22, which reacted with pentan-2,4-dione, ethyl 3-oxobutanoate, maiononitrile or ethyl cyanoacetate to give 23, 24, 26 and 28 . However, methyl isothiocyanate 2 reacted with 2-(cyanomethyl)-l-methylbenzirnidazole 2967 in AfAT-dimethylformamide afford 31 . Also, treatment of 31 with the appropriate hydrazonoyl halides 32a,fa in ethanolic triethylamine at room temperature or treatment of 30 with hydrazonoyl halides 32a or 32b afford 2,3-dihydro-l,3,4-thiadiazoles 34a,b (Sche. Also, each of methylcarbodithioate 37 or thioamide 38 reacted with 32a to give product identical in all respects (mp., mixed mp. and spectra) with 34a. However, methyl isothiocyanate 2 reacted with 2-(cyanomethyl)-l-methylbenzirnidazole 2967 in AfAT-dimethylformamide afford 31 Also, treatment of 31 with the appropriate hydrazonoyl halides 32a,fa in ethanolic triethylamine at room temperature or treatment of 30 with hydrazonoyl halides 32a or 32b afford 2,3-dihydro-l,3,4-thiadiazoles 34a,b . Also, each of methylcarbodithioate 37 or thioamide 38 reacted with 32a to give product identical in all respects (mp., mixed mp. and spectra) with 34a.