Synthesis of functional isoxazole derivatives proceeding from (5-arylisoxazol-3-yl)chloromethanes

Synthesis of functional isoxazole and isothiazole derivatives from [(5-arylisoxazol-3-yl)methoxy]arylmethanols

“…Initial [(5-aryl-1,2-oxazol-3-yl)methoxy]benzaldehydes 1a-1f were synthesized by the Williamson reaction [7], and isoxazole-and isothiazolecarbonyl chlorides 3a-3d were prepared as described in [9][10][11].…”

“…Herein, we describe a procedure for the synthesis of variable functional isoxazole and isothiazole deriva-tives 4-9 by reduction of [(5-aryl-1,2-oxazol-3-yl)methoxy]benzaldehydes 1a-1f [7] with sodium tetrahydridoborate in anhydrous isopropyl alcohol at 20-23°C to the corresponding [(5-aryl-1,2-oxazol-3-yl)methoxy]arylmethanols 2a-2f, followed by acylation with 1,2-oxazole-and 1,2-thiazole-3-carboxylic acid chlorides 3a-3d in anhydrous diethyl ether in the presence of triethylamine at 20-23°C (Scheme 1). Compounds 2a-2f, 4a-4d, 5a-5d, 6a-6d, 7a-7d, 8a-8d, 9c, and 9d were identified on the basis of their elemental compositions and IR, 1 H and 13 C NMR, and mass spectra.…”

Synthesis and Biological Activity of Novel Comenic Acid Derivatives Containing Isoxazole and Isothiazole Moieties

“…Ester 2 further was alkylated with 3-chloromethyl-5phenylisoxazole 3a and 4,5-dichloro-3-chloromethylisothiazole 3b in DMF in the presence of anhydrous K 2 CO 3 and corresponding methyl 4-oxo-5-((5-phenylisoxazol-3-yl)methoxy)-4H-pyran-2carboxylate 4a and methyl 5-((4,5-dichloroisothiazol-3yl)methoxy)-4-oxo-4H-pyran-2-carboxylate 4b were synthesized. Chloromethyl derivatives of isoxazole and isothiazole 3a,b were prepared by reaction of (5-phenylisoxazol-3-yl)methanol and (4,5dichloroisothiazol-3-yl)methanol [21] with thionyl chloride as we reported before [18,22]. It should be noted that the alkylation with chloromethylisoxazole proceeded more slowly than alkylation with chloromethylisothiazole and the yield of ether 4a (51%) is considerably lower than that of ether 4b (78%).…”