تفاعل #160846

معادلة التفاعل

NaOH

Chlorosulfonyl isocyanate

pyrrole

DMF

→

above compound

المردود 73.2%

1H-pyrrole-2,4-dicarbonitrile

المردود 73.2%

المذيبات

EtOAc

ACN

ACN

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةwas cooled in an ice/salt bath
2. 2
   workup.ADDITIONadded to the reaction dropwise over the following 30 min
3. 3
   أخرىThe ice/salt bath was removed
4. 4
   درجة الحرارةThe solution was then cooled in an ice/salt bath
5. 5
   درجة الحرارةto slowly warm to rt over 17 h
6. 6
   درجة الحرارةThe solution was cooled in an ice/salt bath
7. 7
   أخرىThe solution was transferred to a separatory funnel
8. 8
   أخرىthe organic layer was isolated
9. 9
   استخلاصthe aqueous layer was back extracted with EtOAc (2×)
10. 10
    غسيلThe collected organic was washed with aq saturated NaHCO3
11. 11
    استخلاصThe aqueous layers were back extracted with EtOAc (2×50 mL)
12. 12
    أخرىThe combined organic layers were collected
13. 13
    تجفيفdried (MgSO4)
14. 14
    تركيزconcentrated onto silica gel
15. 15
    أخرىpurified by column chromatography (9:1 v/v CH2Cl2-EtOAc)

الإجراء التجريبي

To a solution of ACN (15 mL) was added pyrrole (1.03 mL, 14.9 mmol) which was cooled in an ice/salt bath. Chlorosulfonyl isocyanate (2.73 mL, 31.3 mmol) was diluted in ACN (5 mL) and then added to the reaction dropwise over the following 30 min. The ice/salt bath was removed and the solution was allowed to warm to rt over the next 1.5 h. The solution was then cooled in an ice/salt bath and DMF (5.00 mL, 65.0 mmol) was slowly added via an addition funnel. The solution was allowed to slowly warm to rt over 17 h. The solution was cooled in an ice/salt bath and aq 1 N NaOH (50 mL) was added followed by EtOAc (50 mL). The solution was transferred to a separatory funnel, and the organic layer was isolated and the aqueous layer was back extracted with EtOAc (2×). The collected organic was washed with aq saturated NaHCO3 followed by H2O (100 mL). The aqueous layers were back extracted with EtOAc (2×50 mL). The combined organic layers were collected, dried (MgSO4), concentrated onto silica gel, and purified by column chromatography (9:1 v/v CH2Cl2-EtOAc) to afford 1.28 g of the above compound as a white solid (10.9 mmol, yield 73%). 1H-NMR (DMSO-d6) δ 13.29 (br s, 1H), 8.00 (s, 1H), 7.49 (s, 1H); LCMS RT=1.65 min.

المصدر