Hydrochloric Acid → 2,5-Dimethoxyphenyl isothiocyanate

HRID 231029Notes

Reaction equation

HRID 231029 reaction equation
[CH3:1][O:2][C:3]1[CH:9]=[CH:8][C:7]([O:10][CH3:11])=[CH:6][C:4]=1[NH2:5].C(N(CC)CC)C.[C:19](=S)=[S:20].C1(N=C=NC2CCCCC2)CCCCC1.Cl>O1CCCC1.CCCCCC>[CH3:1][O:2][C:3]1[CH:9]=[CH:8][C:7]([O:10][CH3:11])=[CH:6][C:4]=1[N:5]=[C:19]=[S:20]

Participants

8

Reactant 5

HCID 313Hydrochloric AcidHCID 6348Carbon DisulfideHCID 76132,5-DimethoxyanilineHCID 8471TriethylamineHCID 10868Dicyclohexylcarbodiimide

Product 1

HCID 1424662,5-Dimethoxyphenyl isothiocyanateYield 57.6%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 8058HexaneSolvent

Procedure

To a solution of 2,5-dimethoxyaniline (61.2 g, 0.4 mol) and triethylamine (75 ml, 0.48 mol) in 300 ml of tetrahydrofuran was added carbon disulfide (91.2 g, 0.48 mol) at 5° C. and stirring was continued for 3 hours. To the reaction mixture kept at 5° C. was added N,N'-dicyclohexylcarbodiimide (99 g, 0.48 mol) and stirring was continued for another 3 hours. To the reaction mixture were added 2N HCl solution (100 ml) and hexane (100 ml) and an aqueous layer was separated. n-Hexane (100 ml) was further added to an organic layer and precipitates were filtered off. The solvents were distilled off under reduced pressure and a crude oily product was obtained. Separation and purification by chromatography using a silica gel column gave oily 2,5-dimethoxyphenylisothiocyanate (45 g, yield 57%).

Workup

  1. customkept at 5° C.
  2. stirringstirring
  3. waitwas continued for another 3 hours
  4. customan aqueous layer was separated
  5. additionn-Hexane (100 ml) was further added to an organic layer
  6. customprecipitates
  7. filtrationwere filtered off
  8. distillationThe solvents were distilled off under reduced pressure
  9. customa crude oily product was obtained
  10. customSeparation and purification by chromatography

Sources & evidence

ORD record
ord-39634db7d4e0494d8363146a9ccc688e
Source dataset
uspto-grants-1989_07
Patent number
US04845020

Reaction notes

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