反応 #56284
ord-6123c89ad00749f78063975a5e9d3e64
反応方程式
反応物
試薬
反応条件
後処理
- 1温度while cooling at 0°-5° C.
- 2その他to react for a further 1 hour [until a moistened pH paper
- 3その他The mixture is evaporated in vacuo
- 4その他The organic phase is separated
- 5抽出the aqueous phase is back-extracted twice with a small amount of methylene chloride
- 6抽出each time of a 5% sodium bicarbonate solution [the aqueous phases are back-extracted once each time with a small amount of methylene chloride]
- 7乾燥The combined organic phases are dried over sodium sulfate
- 8その他evaporated
- 9その他The crystalline residue is digested with a small amount of cold ethanol for purification
実験手順
43.5 G. (0.184 mol) of the obtained 3-methylsulfamoyl-thiophene-2-carboxylic acid methyl ester are dissolved in 400 ml. of absolute dimethylformamide are added dropwise at 0° C. during 1 hour to a stirred suspension of 4.5 g. (0.187 mol) of sodium hydride in 50 ml. of absolute dimethylformamide. Then, 40 g. (0.187 mol) of iodoacetic acid ethyl ester dissolved in 50 ml. of absolute dimethylformamide are added dropwise during 2 hours while cooling at 0°-5° C. and the mixture allowed to react for a further 1 hour [until a moistened pH paper shows a pH of 7-8]. The mixture is evaporated in vacuo and the residue taken up with 300 ml. of 0.5-N hydrochloric acid and 300 ml. of methylene chloride. The organic phase is separated, the aqueous phase is back-extracted twice with a small amount of methylene chloride and the combined organic phases are shaken out twice with 100 ml. each time of a 5% sodium bicarbonate solution [the aqueous phases are back-extracted once each time with a small amount of methylene chloride]. The combined organic phases are dried over sodium sulfate and evaporated. The crystalline residue is digested with a small amount of cold ethanol for purification. There is obtained 3-(N-carbethoxymethyl-N-methylsulfamoyl)-thiophene-2-carboxylic acid methyl ester of melting point 83°-85° C.