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).
3-(1H-benzo[d]imidazol-1-yl)propanenitrile (3) was synthesized by
treating of 2 with Chloroacetonitrile in DMF and anhydrous K2CO3 by
stirring at room temperature to afford white powder 3 in 74% yield
(Scheme 2).
The respective nitrile 3 in DMF and sodium azide in th presence of
ammonium chloride was refluxed. The solvent was removed under
reduced pressure. The residue was dissolved in water (50 mL) and
acidified with dilute hydrochloric acid to pH 3. The solution was cooled
in ice bath to give a precipitate which was recrystallized from aqueous
ethanol to afford 1-[(2H-tetrazol-5-yl)methyl]-1H-benzo[d]imidazole 4 as
a white powder in 74 % yield. (Scheme 3).
thyl 2-{5-[(1H-Benzo[d]imidazol-1-yl)methyl]-2H-tetrazol-2-
yl}acetate (5) was prepared in 64% yield by treating of 5 with ethyl
choloroacetate in dry acetone and anhydrous K2CO3 under reflux
(Scheme 4).
The respective ester 5 in absolute ethanol and hydrazine hydrate
was refluxed to afford 2-{5-[(1H-benzo[d]imidazol-1-yl)methyl]-2Htetrazol-2-yl}acetohydrazide (6) in 89% yield (Scheme 5).
The peptides 7-10 were prepared by treating of the acid hydrazide
7 with amino acid ethyl ester hydrochloride (glycine, L-alanine, Lleucine, L-phenylalanine) by azide coupling method in 72-88% yields
(Scheme 6).
The respective ester 7 in absolute ethanol and hydrazine hydrate
was refluxed to afford 2-{5-[(1H-Benzo[d]imidazol-1-yl)methyl]-2Htetrazol-2-yl}-N-(2-hydrazinyl-2-oxoethyl)acetamide (11) in 88% yield
(Scheme 7).
The dipeptides 20-23 were prepared by treating of the acid
hydrazide 19 with amino acid ethyl ester hydrochloride (glycine, Lalanine, L-leucine, L-phenylalanine) by azide coupling method in 78-86%
yields (Scheme 4).
The dipeptides 12-15 were prepared by treating of the acid
hydrazide 11 with amino acid ethyl ester hydrochloride (glycine, Lalanine, L-leucine, L-phenylalanine) by azide coupling method to give
12-15 in 78-86% yields (Scheme 8).
3-{2-[(1H-benzo[d]imidazol-1-yl)methyl]-1H-benzo[d]imidazol-1-
yl}propanenitrile (18) was synthesized by treating of 17 with
acrylonitrile in ethanol and drops of TEA by reflux for 4 h. to afford 18
as a white powder in 74% yield (Scheme 10).
2-[(1H-Benzo[d]imidazol-1-yl)methyl]-1-[2-(2H-tetrazol-5-
yl)ethyl]-1H-benzo[d]imidazole (19) was synthesized by stirring The
respective nitrile 18 in DMF and sodium azide In th presence of
ammonium chloride was refluxed to afford 19 as a white powder in 88 %
yield. (Scheme 11).
Ethyl 2-{5-{2-{2-[(1H-benzo[d]imidazol-1-yl)methyl]-1Hbenzo[d]imidazol-1-yl}ethyl}-2H-tetrazol-2-yl}acetate (20) was prepared
in 64% yield by treating of 19 with ethyl choloroacetate in dry acetone
and anhydrous K2CO3 under reflux (Scheme 12).
The respective ester 20 in absolute ethanol and hydrazine hydrate
was refluxed to afford 2-{5-{2-{2-[ (1H-benzo[d]imidazol-1-yl)methyl]-
1H-benzo[d]imidazol-1-yl}ethyl}-2H-tetrazol-2-yl}acetohydrazide (21)
in 89% yield (Scheme 13).
The peptides 22-25 were prepared by treating of the acid
hydrazide 21 with amino acid ethyl ester hydrochloride (glycine, Lalanine, L-leucine, L-phenylalanine) by azide coupling method to afford
the corresponding peptides 22-25 in 75-81% yields (Scheme 14).
2-{{5-[(1H-benzo[d]imidazol-1-yl)methyl]-1,3,4-oxadiazol-2-
yl}thio}acetonitrile (28) was synthesized by treating of 27 with
Chloroacetonitrile in DMF and anhydrous K2CO3 by stirring at room
temperature to afford yellow syrup 28 in 74% yield. (Scheme 17).
The respective nitrile 28 in DMF and sodium azide in th presence of
ammonium chloride was refluxed to afford 2-[(1H-Benzo[d]imidazol-1-
yl)methyl)-5-{[(2H-tetrazol-5-yl)methyl]thio}-1,3,4-oxadiazole (29) as a
yellow syrup, yield 75%. (Scheme 18).
Ethyl 2-{5-{{{5-[(1H-benzo[d]imidazol-1-yl)methyl]-1,3,4-
oxadiazol-2-yl}thio}methyl}-2H-tetrazol-2-yl}acetate (30) was
synthesized by treating of 2 with ethyl chloloroacetate in dry acetone and
anhydrous K2CO3 either by reflux or by microwave irradiation to afford
a yellow syrup 30 in 64 % yield. (Scheme 19).
The respective ester 30 in absolute ethanol and hydrazine hydrate
was refluxed or irradiated [microwave (MW) oven (master KOG 840-P,
output 1500W) and silica gel] to afford 2-{5-{{{5-[(1Hbenzo[d]imidazol-1-yl)methyl]-1,3,4-oxadiazol-2-yl}thio}methyl}-2Htetrazol-2-yl}acetohydrazide (31) as yellow syrup, yield 89% (Scheme
31).
The peptides 32-35 were prepared by treating of the acid hydrazide
31 with amino acid ethyl ester hydrochloride (glycine, L-alanine, Lleucine, L-phenylalanine) by azide coupling method to afford the
corresponding peptides 32-35 in 72-88% yields (Scheme 21).