2-Phenyl-1,3-thiazole-4-carbaldehyde → 4-(2,4-Dioxothiazolidin-5-yl)methyl-2-[(phenylthiazol-4-yl)methylidene]aminophenol
Reaction equation
[NH2:1][C:2]1[CH:3]=[C:4]([CH:13]=[CH:14][C:15]=1[OH:16])[CH2:5][CH:6]1[S:10][C:9](=[O:11])[NH:8][C:7]1=[O:12].[C:17]1([C:23]2[S:24][CH:25]=[C:26]([CH:28]=O)[N:27]=2)[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1>C(O)C>[O:11]=[C:9]1[NH:8][C:7](=[O:12])[CH:6]([CH2:5][C:4]2[CH:13]=[CH:14][C:15]([OH:16])=[C:2]([N:1]=[CH:28][C:26]3[N:27]=[C:23]([C:17]4[CH:18]=[CH:19][CH:20]=[CH:21][CH:22]=4)[S:24][CH:25]=3)[CH:3]=2)[S:10]1Participants
4
Procedure
A mixture of 500 mg of 5-(3-amino-4-hydroxybenzyl)-2,4-dioxothiazolidine, 405 mg of 2-phenyl-4-formylthiazole and 30 ml of ethanol is refluxed for 20 minutes, and the solvent is distilled off. 840 mg of 4-(2,4-dioxothiazolidin-5-yl)methyl-2-[(phenylthiazol-4-yl)methylidene]aminophenol obtained as a crude product are dissolved in 40 ml of benzene, and 1.26 g of lead tetraacetate are added thereto. After the mixture is stirred at room temperature for 15 minutes, the solvent is distilled off. Ethyl acetate and water are added to the residue, and the ethyl acetate layer is washed with water, dried, and evaporated to remove the solvent. The residue is purified by silica gel column chromatography (solvent; chloroform:methanol=100:1), whereby 400 mg of 5-[(2,4-dioxothiazolidin-5-yl)methyl]-2-(2-phenyl-1,3-thiazol-4-yl)benzoxazole are obtained. The Mass and IR data of this product are identical with those of the product obtained in Example 8.