Hydrochloric Acid → 2-Oxindole-1-carboxamide

HRID 1906556Notes

Reaction equation

HRID 1906556 reaction equation
[NH:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH2:3][C:2]1=[O:10].ClS([N:15]=[C:16]=[O:17])(=O)=O.Cl.O>C1(C)C=CC=CC=1>[N:1]1([C:16]([NH2:15])=[O:17])[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH2:3][C:2]1=[O:10]

Participants

6

Reactant 4

HCID 313Hydrochloric Acid2×HCID 962WaterHCID 70918Chlorosulfonyl isocyanateHCID 321710Oxindole

Product 1

HCID 115172742-Oxindole-1-carboxamideYield 53.7%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A mixture of 2-oxindole (5.86 g, 44.0 mmoles) in toluene (160 ml) was azeotroped for one hour to dry the toluene. Then, chlorosulfonyl isocyanate (7.47 g, 52.8 mmole) was added. Hydrogen chloride was immediately evolved. The mixture was stirred and refluxed for 15 minutes and then cooled to room temperature. Water (50 ml) was added to the cooled mixture (some HCl was initially evolved) and the mixture stirred for 1.5 hours. The solid which formed was collected by filtration and dried (4.10 g). The filtrate was extracted with ethyl acetate (100 ml), the resulting extract washed with brine (2×100 ml) and dried (MgSO4). Evaporation of the extract under reduced pressure gave 4.16 g of solid. The combined solids were recrystallized by dissolution in acetonitrile (200 ml) followed by concentration of the solution under reduced pressure to about 75 ml. The small amount of amorphous material which separated was filtered off, the filtrate decolorized and concentrated under reduced pressure to about 50 ml volume, then seeded. The dark red crystals which separated were filtered and dried (3.0 g; 38%). It was identical to the product of Example 1.

Workup

  1. customwas azeotroped for one hour
  2. dry with materialto dry the toluene
  3. temperaturerefluxed for 15 minutes
  4. stirringstirred for 1.5 hours
  5. customThe solid which formed
  6. filtrationwas collected by filtration
  7. customdried (4.10 g)
  8. extractionThe filtrate was extracted with ethyl acetate (100 ml)
  9. extractionthe resulting extract
  10. washwashed with brine (2×100 ml)
  11. dry with materialdried (MgSO4)
  12. customEvaporation of the
  13. extractionextract under reduced pressure

Sources & evidence

ORD record
ord-6d762df980c941a9b66737c433d1e2db
Source dataset
uspto-grants-1987_03
Patent number
US04652658

Reaction notes

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