تفاعل #6526

معادلة التفاعل

pyrrole-2-carboxylic acid

2-aminothiophenol

boric acid

→

2-(pyrrol-2-yl)benzothiazole

المردود 14.0%

المذيبات

xylene

ethyl acetate

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةwas heated
2. 2
   درجة الحرارةunder reflux for 3 days
3. 3
   أخرىwhile removing water which
4. 4
   أخرىwas generated from reaction
5. 5
   أخرىthe cooled reaction mixture
6. 6
   غسيلwashed with 200 mL of 5% sodium hydroxide solution
7. 7
   تجفيفThe separated organic layer was dried over anhydrous sodium sulfate
8. 8
   أخرىThe resulting crude product was purified by column chromatography on silica gel with 10% ethyl acetate in hexane as eluant

الإجراء التجريبي

A mixture of 5.55 g (50 mmol) of pyrrole-2-carboxylic acid, 6.26 g (50 mmol) of 2-aminothiophenol and 3.09 g (50 mmol) of boric acid in 250 mL of xylene was heated under reflux for 3 days while removing water which was generated from reaction using a Dean-Stark trap. the cooled reaction mixture was diluted with 200 mL of ethyl acetate, washed with 200 mL of 5% sodium hydroxide solution and then with 200 mL of water. The separated organic layer was dried over anhydrous sodium sulfate. The resulting crude product was purified by column chromatography on silica gel with 10% ethyl acetate in hexane as eluant. The desired product, 2-(pyrrol-2-yl)benzothiazole (1.40 g, 14%) was obtained as a pale yellow solid. m.p. 150°-151° C.; 1H-NMR (CDCl3) 6.32-6.35 (m, 1H, ArH), 6.87-6.89 (m, 1H, ArH), 6.94-6.96 (m, 1H, ArH), 6.33 (t, 1H, ArH), 6.43 (t, 1H, ArH), 7.84 (d, 1H, ArH), 7.90 (d, 1H, ArH).

المصدر