Triethylamine → Methyl 3-isocyanatothiophene-2-carboxylatato

HRID 1870532Notes

Reaction equation

HRID 1870532 reaction equation
[O:1]=[C:2](Cl)OC(Cl)(Cl)Cl.[NH2:9][C:10]1[CH:14]=[CH:13][S:12][C:11]=1[C:15]([O:17][CH3:18])=[O:16].C(N(CC)CC)C>O1CCOCC1>[N:9]([C:10]1[CH:14]=[CH:13][S:12][C:11]=1[C:15]([O:17][CH3:18])=[O:16])=[C:2]=[O:1]

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 10426DiphosgeneHCID 89652Methyl 3-amino-2-thiophenecarboxylate

Product 1

HCID 18696616Methyl 3-isocyanatothiophene-2-carboxylatato

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Procedure

Diphosgene (4.6 mL) was added dropwise to a solution of methyl 3-amino-2-thiophenecarboxylate (5.0 g) in p-dioxane (100 mL) at room temperature under N2. Triethylamine (5.3 mL) was then added with concomitant formation of a white precipitate. The resulting reaction mixture was heated at reflux overnight. The reaction was allowed to cool to room temperature and then filtered to remove solid impurities. The precipitate was rinsed with diethyl ether (about 250 mL) and the filtrate was concentrated under reduced pressure to yield 6.4 g of crude title compound of Step A as a brown solid. 1H NMR (CDCl3): δ 7.43 (d,1H), 6.78 (d,1H), 3.92 (s,3H).

Workup

  1. customThe resulting reaction mixture
  2. temperaturewas heated
  3. temperatureat reflux overnight
  4. filtrationfiltered
  5. customto remove solid impurities
  6. washThe precipitate was rinsed with diethyl ether (about 250 mL)
  7. concentrationthe filtrate was concentrated under reduced pressure

Sources & evidence

ORD record
ord-cfab7b1c4a6843019e0cb39045efbcef
Source dataset
uspto-grants-2000_08
Patent number
US06096895

Reaction notes

Loading…