반응 #4503

반응 방정식

(Z)-5-{4-[2-(5-methyl-2-phenyl-4-oxazolyl)ethoxy]benzylidene}-2,4-thiazolidinedione

→

(E)-5-{4-[2-(5-methyl-2-phenyl-4-oxazolyl)ethoxy]benzylidene}-2,4-thiazolidinedione

수율 20.0%

용매

acetonitrile

반응 조건

후처리

1. 1
   workup.DISTILLATIONThe solvent was distilled off
2. 2
   기타the resulting crystals were chromatographed on a column of silica gel (200 g)
3. 3
   세척Elution with hexane-ethyl acetate (1:1, V/V)

실험 절차

A solution of (Z)-5-{4-[2-(5-methyl-2-phenyl-4-oxazolyl)ethoxy]benzylidene}-2,4-thiazolidinedione (200 mg) in acetonitrile (750 ml), in a quartz tube under a stream of nitrogen, was irradiated by a 300 W high-pressure mercury lamp for 3 hours. The solvent was distilled off, and the resulting crystals were chromatographed on a column of silica gel (200 g). Elution with hexane-ethyl acetate (1:1, V/V) gave (E)-5-{4-[2-(5-methyl-2-phenyl-4-oxazolyl)ethoxy]benzylidene}-2,4-thiazolidinedione (40 mg, 20.0%). Recrystallization from dichloromethaneethanol yielded colorless needles, m.p. 216°-217° C. Elemental analysis for C22H18N2O4S; Calcd.: C, 65.01; H, 4.46; N, 6.89. Found: C, 64.69; H, 4.26; N, 7.11. The subsequent elution with hexane-ethyl acetate (1:1, V/v) allowed the recovery of (Z)-5-{4-[2-(5-methyl-2-phenyl-4-oxazolyl)ethoxy]benzylidene}-2,4-thiazolidinedione (138 mg, 69.0%).

출처