Tikrit Journal of Pure Science

T his study includes synthesis of some benzothiazole derivatives from treatment 2 -aminothiazole with choroacyle chloride to form 1-hydrogen-benzothiazole-2yl-2-chloroastiamide (1).the last one was reacted with urea, thiurea, thiosymigarizaide, 2-amibenzothiazole and para-aminoaniline, respectively to form the compounds (2,6). Some shiff bases for 2-aminobenzothiazole (7,8) were prepared from the reacting with aromatic aldehydes and it was cycled by reaction with glycine to form two derivatives of amidazolidine (9,10). The prepared compounds were diagnosed by IR spectra and H 1 NMR for proton, then, the bacterial susceptibility towards some prepared compounds (1,2,5,6,7) were estimated against E.coli and Proteus mirabilis


1-Introduction
Thiazole derivatives occupy an im portant position among heterocycle that are containing N and S atoms [1,2], several of thiazole derivatives are charachterized by their biological and pharmacological activity [3,4], therefore, it was studied at a wide range including several fields.thiazole cycle plays an important role in medicine [5] due to using it as antibiotic drugs against microbes [6], tuberculosis [7], viruses [8], malaria [9] and HIV [10] also in development of allergy [11] and in synthesis of sulfonylamide [12].Benzothiazoles are used as anticancer [13] with mixture of amino acids complexes that introduced into the transference and replacement mechanisms of trace elements ions in human body [14].The nucleus of benzothiazole are linkaged with various activities of antihistamine [15], some of chloride-cobalt complexes which contain benzothiazole were also showed high activity in increasing of agriculture production [16].the functional benzothiazole was reported to show the reverse applications as light stabilizer and complexity factors with metal [17] .

2-2 Bacterial susceptibility test for some prepared compounds (1-2-5-6-7)
Two species of pathogenic bacteria, that resistance to antibiotics, were used , which were E.coli and Proteus Mirabilis.the bacterial isolates were taken ready and diagnosed from laboratory of biology department in education collage of pure science / Tikrit university.2-2-1 culture media a-Nutrient broth: it was prepared and used according to the company's instructions, it sterilized by autoclave at 121°C for 15 min.under 15bar/inch 2 .then, poured in petri dishes or special tubes and left to cool [22] b-Muller Hinton agar: this medium is used to measure the biological activity for antibiotics and pharmacological, also is used to measure the diameter of inhibition zone [23].

2-2-2 Chemical solutions
The chemical solutions for some prepared compounds were prepared at concentration (0.01-0.1 gm/5ml) and sterilized by autoclave at 121°C for 15 min under 15 bar/inch 2 , then left to cool before used .

2-2-3 Estimation of biological activity by diffusion methods
The biological activity was estimated by followed a Kirby Bauer method ; it has been spread (0.1ml) from bacterial suspension on the petri dishes that containing muller hinton agar and left for 5 min.to diffuse into medium.after that, 4 pores in each dishes were done using sterilize cort porer (5mm diameter).(0.1 ml) from prepared solutions were added to each pores while the fourth pore filled by DMSO as control sample.All dishes were incubated for 24 hr.at 37°C [24][25].The inhibition diameter was measured around each pore in Mm according to Preslott method [26] Results and discussion: The amino group in 2-aminobenzothiazole reacted with chloroacetyl chloride to form the compound (1) as shown in table (1) and figure (5).The IR spectra for this compound showed absorption band at 3506cm -1 for stretch of (NH ) bond and the absorption band at 1693 cm -1 for stretch of(C=O)bond, and also at 715 cm -1 for (C=C) bond.The H-NMR spectra of this compound was showed a dual signal at frequency (4.46-4.51δ ppm) attributed to (2H,CH 2 ) protons, and a signal at (8 δ ppm) to ( H, NH)proton, as well as, a signal showed at range (7.24-7.98 δppm) attributed to (4H, phenyl group) as shown in figure (1).The compound (1) was reacted with urea and thiurea to formed oxazole and thiazole (2-3) respectively .IR spectra for these compounds showed absorption band at (3465 cm -1 ) attributed to stretch (NH 2 ) bond , and at ( 1155cm -1 ) to stretch of( C-O ) band .as shown in table (1).The compound (1) was reacted with thiocymicambarzide and 2-aminobenzothiazole and para aminoaniline to form compounds (4-5-6).IR spectra for these compounds showed absorption band at range (3506-3382 cm -1 ) attributed to stretch of (N-H) bond , also at (1666-1616cm -1 ) to stretch of (C=O) bond, and at (1242 cm -1 ) to (C=S) bond, as shown in table (2).H-NMR spectra was showed a dual signal for compound (5) at range (3.59-3.66δppm)attributed to (2H-CH 2 ) proton, and a single signal at (4.15 δppm) to (H, CH 2 -NH) proton, and at (7.96 δ ppm) to (H, NH-CO) proton, also H-NMR showed a signal at (6.99-7.68δppm) attributed to (8H,phenyl group), as shown in figure (2).The compound 2-aminobenzothiazole was also reacted with aromatic aldehydes to form shiff bases of compounds (7-8), IR spectra showed absorption band for these compounds at range (1631-1643 cm -1 ) attributed to stretch (C=O) bond, also at (744 cm -1 ) to stretch (C-Cl) bond and (3392 cm -1 ) to stretch (C-OH) bond as shown in table (3)and figure (6).H-NMR spectra for compound (7) showed a signal at (10 δ ppm) attributed to (H-CH ) proton, as well as, a signal at range (6.97-7.95δppm) to (8H-phenyl group), as shown in figure (3), while compound (8) was showed a signal at ( 3.39 δ ppm) attributed to (H,OH) proton and a signal at range (7.64 δppm) to (H-CH) proton, as well as, a signal showed at range (6.62-6.97δ ppm) attributed to (8H, phenyl group) proton , as shown in figure (4).The compound (7-8) were cycled using glycine and THF as solvent to formation amideazoldine-4-on compounds that represent by compounds (9)(10).IR spectra for these compounds was showed absorption band at range (1633-1683 cm -1 ) attributed to stretch of (C=O) bond , also at (3332-3402 cm -1 ) to stretch of (N=H) bond as shown in table (4) .Biological activity for some compounds (1-2-5-6-

7)
The biological activity of some compounds (1-2-5-6-7) was measured ,where compounds (1-2) showed a high efficiency towards Proteus mirabilis (susceptibility), also compound (6) showed an efficiency towards E.coli, while the rest compounds were ineffective towards these species of bacteria but compound (5) was had a low efficiency towards E.coli.as shown in table (5).