الفهرس 
Biological Screening
GENRAL PROCEDUREOnly 14 pages are availabe for public view
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Abstract
This following synthetic work is classified into three main sections:
In Section A: we discuss for one-pot synthesis to give the target a single regioisomer
3-amino-2-hydroxy-thiazolo[3,2-a]pyrimidin-5-one derivative (17) not 23 in a good
yield.
In Section B : synthesis of 3-amino-2-hydrazinyl-thiazolo[3,2-a]pyrimidin-5-one
derivative (26) by direct hydrazinolysis of compound 17 with hydrazine hydrate. The
key compound 26 used for the preparation of Pyrimido-thiazolo[4,5-e][1,2,4]triazin-
6-one derivative (27) and 8-methyl-pyrimido[2’,1’:2,3]thiazolo[4,5-e][1,2,4]triazin-6-
one derivative (28). pyrimido-thiazolo[4,5-e][1,2,3,4]tetrazin-9-one derivative (29)
produced by reaction with nitrous acid. Ethyl -3-(2-(3-amino-thiazolo[3,2-
a]pyrimidin-2-yl) hydrazono) butanoate (31) and N’-(3-amino-thiazolo[3,2-
a]pyrimidin-2-yl)-2-cyanoacetohydrazide (37) resulted by condensation reaction with
ethylacetoacetate or ethylcyanoacetate in absolute ethanol. 2-Pyrazolyl derivatives 30,
34 and 39 furnished by cyclo condensation reaction with acetyl acetone ,
ethylacetoacetate or ethylcyanoacetate, respectively. The Schiff’s basis (36a-f) are
resulted also as shown in (Scheme A). 2-amino-2-hydrazino derivative (26)
2-Amino-2-hydrazino derivative (26) condensed with the appropriate aromatic or
hetero aromatic aldehyde namely: 4-methoxybenzaldehyde, 4-chlorobenzaldehyde, 4-
fluorobenzaldehyde, benzaldehyde, 4-nitrobenzaldehyde, and 2-thiophenaldehyde to
yield the corresponding Schiff‘s bases 40a-f. Bromination reaction of the
corresponding Schiff‘s bases 40a,b,f carried out to afford 3-amino-6-bromo-2-(2-(4-
arylidene)hydrazinyl)-7-methyl-5H-thiazolo[3,2-a]pyrimidin-5-one derivatives
(41a,b,f).
The azo methine moiety of the Schiff‘s bases (40a,d-f) underwent cyclo addition
reaction upon treatment with thioglycolic acid to yield 2-thiazolidinone derivatives
(44a,d-f) (Scheme B
The corresponding N-glycoside 45(a,e) were synthesized by condensing 2-amino-2-
hydrazino derivative (26) with the appropriate linear sugar namely; D(+) arabinose
and D (+) xylose, D(+) glucose, D(+) galactose, and D(+) manose. The corresponding
N-glycoside 45(a,e) and their acetylated acyclo analogs 46(a,e) (Scheme C).
In Section C : the corresponding Schiff‘s bases 47a-f afforded by condensing the
target compound 3-amino-2-hydroxy-thiazolo[3,2-a]pyrimidin-5-one (17) with
aldehydes namely; 4-chlorobenzaldehyde, 4- methoxy benzaldhyde, 4-fluro
benzaldehyde, benzaldhyde, 4-nitro benzaldhyde and thiophene-2-carboxaldehyde in
dry dioxane of.
(Scheme D) showed that the prepared Schiff bases 47a-f were used as key precursors
for the synthesis of 3-thiazolidinyl derivatives (49a-f). This reaction including addition
of thioglycolic acid on the azomethine moiety of the corresponding Schiff‘s bases
47a-f followed by cyclo-condensation reaction to afford 3-thiazolidinyl derivatives
(49a-f)