الفهرس 
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Abstract
1H-Benzo[d]imidazole (2) was prepared by treatment of ophenylenediamine
(1) in 98% formic acid either by reflux or by
microwave irradiation followed by basification by sodium carbonate to
give white prisms 2 in 88-98% yield (Scheme 1).
Ethyl 2-(1H-benzo[d]imidazol-1-yl)acetate (3) was synthesized by
treating of 2 with ethyl choloroacetate in dry acetone and anhydrous
K2CO3 either by reflux or by microwave irradiation to afford white
powder 3 in 71-98% yield (Scheme 1).
The respective ester 3 in absolute ethanol and hydrazine hydrate
was refluxed or microwave irradiated to afford 2-(1H-benzo[d]imidazol-
1-yl)acetohydrazide (4) 89-98% yield (Scheme 1).
A solution of the respective hydrazide 4 in CS2 and aqueous
solution KOH and ethanol was refluxed for 4h and the solvents were
evaporated to dryness under reduced pressure. The obtained solid was
dissolved in water and acidified with conc. HCl. The precipitate was
filtered off. Washed with water, and recrystallized from ethanol to afford
5-[(1H-benzo[d]imidazol-1-yl)methyl]-1,3,4-oxadiazole-2-thiol (5) as
yellow powder in 83% yield (Scheme 1).