Water → 1-Methyl-3-(4-cyano-3-(dipropylamino)-5-isothiazolyl)urea

HRID 616510Notes

Reaction equation

HRID 616510 reaction equation
[NH2:1][C:2]1[S:6][N:5]=[C:4]([N:7]([CH2:11][CH2:12][CH3:13])[CH2:8][CH2:9][CH3:10])[C:3]=1[C:14]#[N:15].[CH3:16][N:17]=[C:18]=[O:19].O>C([O-])(=O)C.C([O-])(=O)C.C([Sn+2]CCCC)CCC.O1CCCC1>[CH3:16][NH:17][C:18]([NH:1][C:2]1[S:6][N:5]=[C:4]([N:7]([CH2:11][CH2:12][CH3:13])[CH2:8][CH2:9][CH3:10])[C:3]=1[C:14]#[N:15])=[O:19]

Participants

6

Reactant 3

HCID 962WaterHCID 12228Methyl IsocyanateHCID 203675715-Amino-4-cyano-3-(dipropylamino)isothiazole

Product 1

HCID 203675861-Methyl-3-(4-cyano-3-(dipropylamino)-5-isothiazolyl)ureaYield 70.6%

Reagents, catalysts & solvents 2

HCID 9798523Di-n-butyl diacetoxy tinCatalystHCID 8028TetrahydrofuranSolvent

Procedure

A solution of 7.0 g of 5-amino-4-cyano-3-(dipropylamino)isothiazole, 3.6 g of methyl isocyanate and 40 drops of dibutyltin diacetate in 50 ml of tetrahydrofuran was heated under reflux overnight. Thin-layer chromatographic analysis indicated the reaction to be complete. The reaction mixture was poured into rapidly stirred, cold water. The solid precipitate was collected by filtration. The filtrate was extracted with methylene chloride. The solid was combined with the extract and the mixture dried over calcium chloride, then filtered through magnesium sulfate. The filtrate was concentrated under reduced pressure and the residue was taken up in a mixture of toluene and benzene to which a little ethanol had been added. Pentane was then added to promote crystallization. The recrystallization yielded 6.2 g of 1-methyl-3-(4-cyano-3-(dipropylamino)-5-isothiazolyl)urea, m.p. 179°-180°. The nmr and ir spectra were consistent with the assigned structure.

Workup

  1. temperatureunder reflux overnight
  2. customthe reaction
  3. additionThe reaction mixture was poured
  4. filtrationThe solid precipitate was collected by filtration
  5. extractionThe filtrate was extracted with methylene chloride
  6. extractionextract
  7. dry with materialthe mixture dried over calcium chloride
  8. filtrationfiltered through magnesium sulfate
  9. concentrationThe filtrate was concentrated under reduced pressure
  10. additionthe residue was taken up in a mixture of toluene and benzene to which a little ethanol
  11. additionhad been added
  12. additionPentane was then added
  13. customcrystallization
  14. customThe recrystallization

Sources & evidence

ORD record
ord-a65740f8c0fc4d549f416164d9bb1b87
Source dataset
uspto-grants-1978_02
Patent number
US04075001

Reaction notes

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