Phosgene → Methyl 2-[(oxomethylidene)sulfamoyl]cyclopent-1-ene-1-carboxylate
Reaction equation
[NH2:1][S:2]([C:5]1[CH2:9][CH2:8][CH2:7][C:6]=1[C:10]([O:12][CH3:13])=[O:11])(=[O:4])=[O:3].C(N=[C:19]=[O:20])CCC.C1N2CCN(CC2)C1.C(Cl)(Cl)=O>>[C:10]([C:6]1[CH2:7][CH2:8][CH2:9][C:5]=1[S:2]([N:1]=[C:19]=[O:20])(=[O:3])=[O:4])([O:12][CH3:13])=[O:11]Participants
Procedure
In 75 ml of dry xylenes was placed 4.0 g of methy 2-(aminosulfonyl)-1-cyclopentene-1-carboxylate (VIII), 6.5 ml of n-butyl isocyanate, and 0.05 g of DABCO. The mixture was heated to reflux (ca 138°) then contacted with an excess of phosgene which was condensed into the mixture from a dry-ice condenser until the reflux temperature dropped to 126°. Over several hours the temperature increased to 135° and additional phosgene was condensed into the mixture, again, lowering the temperature to 129°. This process was repeated until no temperature increase could be observed, indicating complete consumption of the sulfonamide. The mixture was then cooled and the xylenes removed under reduced pressure to yield ca 5 g of an amber oil. An infrared spectrum (neat) exhibited a strong absorption at 2230 cm-1 indicating the title compound.
Workup
- temperatureThe mixture was heated
- temperatureto reflux (ca 138°)
- customcondensed into the mixture from a dry-ice condenser until the reflux temperature
- additiondropped to 126°
- temperatureOver several hours the temperature increased to 135°
- customcondensed into the mixture
- customto 129°
- temperatureincrease could
- customconsumption of the sulfonamide
- temperatureThe mixture was then cooled
- customthe xylenes removed under reduced pressure
Sources & evidence
- ORD record
- ord-75fdae4b16ee47f28eca2f2f859da84f
- Source dataset
- uspto-grants-1984_07
- Patent number
- US04461640
Reaction notes
Loading…