Abstract
Substituted[4,5]thieno[2,3-
d
]thiazolo[3,2-
a
]pyrimidin-5-one (
3a–b
) and pyrimidin-5(6
H
)-imine (
3c–e
) were synthesized via reaction of the starting compounds, ethyl 2-amino-substituted[
b
]thiophene-3-carboxylate (
2a–c
) and 2-amino-substituted [
b
]thiophene-3-carbonitrile (
2d–f
), respectively, with 2-bromothiazole. Synthesis of (bromo-substituted[
b
]thiophen-2-yl)alkanamide derivatives (
4a–e
) and thieno[2,3-
d
][1,3]oxazin-4-imine derivative (
5
) was accomplished via reaction of the starting compounds with bromoalkyl chloride through nucleophilic substitution; however, for the synthesis of compound
5
, nucleophilic substitution was followed by nucleophilic addition to a nitrile group to form the oxazinimine ring. 1-(3-cyano-substituted[
b
]thiophen-2-yl)-3-(4-(trifluoromethyl)phenyl)thiourea derivatives (
6a–c
) were obtained via reaction of the starting compounds (
2d–f
) and 4-(trifluoromethyl phenyl)isothiocyanate. The lead compounds (
2d–f
) rapidly reacted with 4-(trifluoromethyl)benzaldehyde or 4-(2-pyridyl)benzaldehyde in acidic medium to yield compounds (
7a–f)
in large quantities. X-ray crystallography of compounds
4c
and
7e
confirmed their structures. Antimicrobial studies revealed that compound
6a
was equally potent to ampicillin against
Bacillus
strains. Moreover, compounds
3e
,
4d
, and
6a
possessed greater anti-inflammatory potency than that of the standard drug.