Chloroform → Methyl 2-isothiocyanatothiophene-3-carboxylate

HRID 1384853Notes

Reaction equation

HRID 1384853 reaction equation
[NH2:1][C:2]1[S:3][CH:4]=[CH:5][C:6]=1[C:7]([O:9][CH3:10])=[O:8].C(Cl)(Cl)Cl.[C:15](Cl)(Cl)=[S:16].C(=O)(O)[O-].[Na+]>O>[N:1]([C:2]1[S:3][CH:4]=[CH:5][C:6]=1[C:7]([O:9][CH3:10])=[O:8])=[C:15]=[S:16]

Participants

6

Reactant 4

HCID 6212ChloroformHCID 10040ThiophosgeneHCID 78381Methyl 2-amino-3-thenoateHCID 516892Sodium Bicarbonate

Product 1

HCID 2759916Methyl 2-isothiocyanatothiophene-3-carboxylateYield 65.1%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

In a sulfonation flask, 50.2 g (0.32 mol) of methyl 2-aminothiophene-3-carboxylate are added to 480 ml of chloroform and 320 ml of water. Then 40.5 g (0.35 mol) of thiophosgene and 1000 ml of saturated aqueous sodium bicarbonate solution are added simultaneously in 40 minutes under stirring. The stirring continued for 1 h at room temperature and then the organic phase is separated. The water phase is extracted twice with chloroform and the organic phase dried over sodium sulfate. After removal of the chloroform in the water-jet vacuum 61.3 g of a dark oil is obtained, which is further purified by column chromatography over silica gel (eluant: ethyl acetate/hexane=1:5). 41.5 g of methyl 2-isothiocyanatothiophene-3-carboxylate are obtained in the form of a brown powder having a melting point of 63-65° C.

Workup

  1. customthe organic phase is separated
  2. extractionThe water phase is extracted twice with chloroform
  3. dry with materialthe organic phase dried over sodium sulfate
  4. customAfter removal of the chloroform in the water-jet vacuum 61.3 g of a dark oil
  5. customis obtained
  6. customwhich is further purified by column chromatography over silica gel (eluant: ethyl acetate/hexane=1:5)

Sources & evidence

ORD record
ord-5d1e9eac78e5473e8427f598d3500dce
Source dataset
uspto-grants-2001_07
Patent number
US06262058B1

Reaction notes

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