Ethyl 2-chloroacetoacetate → Ethyl 2-anilino-4-methyl-1,3-thiazole-5-carboxylate
反応式
[C:1]1([NH:7][C:8]([NH2:10])=[S:9])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.Cl[CH:12]([C:18](=O)[CH3:19])[C:13]([O:15][CH2:16][CH3:17])=[O:14]>C(O)C>[CH3:19][C:18]1[N:10]=[C:8]([NH:7][C:1]2[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=2)[S:9][C:12]=1[C:13]([O:15][CH2:16][CH3:17])=[O:14]参加物
4
実験手順
To 70 ml of ethanol, 10.7 g (70 mmol) of phenylthiourea and 11.6 g (70 mmol) of ethyl 2-chloro-3-oxobutanate were dissolved, followed by heating under refluxing for 8 hours. The reaction liquid was concentrated and dissolved in ethyl acetate and the organic layer was washed with an aqueous solution of sodium carbonate, water and a saturated saline solution in this order, followed by drying over anhydrous magnesium sulfate and concentrating under reduced pressure. Solid obtained was washed with diisopropyl ether to obtain 16.8 g (yield: 91%) of ethyl 4-methyl-2-(N-phenylamino)thiazole-5-carboxylate. (2) To 50 ml of ethanol, 12.8 g (49 mmol) of ethyl-4-methyl-2-(N-phenylamino)thiazole-5-carboxylate was dissolved, followed by adding 24 g (150 mmol) of 25% sodium hydroxide aqueous solution, and stirring at 80° C. for 15 hours. The reaction liquid was poured into ice water, and acetic acid was added to make acidic. Crystal precipitated was filtered, washed with water and a mixed solvent of hexane/ethyl acetate and dried to obtain 5.50 g (yield: 48%) of 4-methyl-2-(N-phenylamino)thiazole-5-carboxylic acid.