Triethylamine → Ethyl 5-(3,4-dimethoxy-5-nitrophenyl)-4-oxazolecarboxylate

HRID 2254780Notes

Reaction equation

HRID 2254780 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:9]=[C:10]([N+:14]([O-:16])=[O:15])[C:11]=1[O:12][CH3:13])[C:6](Cl)=[O:7].[N+:17]([CH2:19][C:20]([O:22][CH2:23][CH3:24])=[O:21])#[C-:18].C(N(CC)CC)C>O1CCCC1>[CH3:1][O:2][C:3]1[CH:4]=[C:5]([C:6]2[O:7][CH:18]=[N:17][C:19]=2[C:20]([O:22][CH2:23][CH3:24])=[O:21])[CH:9]=[C:10]([N+:14]([O-:16])=[O:15])[C:11]=1[O:12][CH3:13]

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 533707Ethyl isocyanoacetateHCID 219286153,4-Dimethoxy-5-nitrobenzoyl chloride

Product 1

HCID 21459162Ethyl 5-(3,4-dimethoxy-5-nitrophenyl)-4-oxazolecarboxylate

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

A solution of 2.5 g of 3,4-dimethoxy-5-nitrobenzoyl chloride in 10 ml of absolute tetrahydrofuran is treated with 1.1 ml of ethyl isocyanoacetate and subsequently with a solution of 3.0 ml of triethylamine in 10 ml of tetrahydrofuran and stirred at room temperature for 48 hours. After distillation of the solvent, the residue is extracted with ethyl acetate/water. The crude product obtained after evaporation is chromatographed on a 20-fold amount of silica gel with ethyl acetate. After recrystallization from ethyl acetate/hexane there is obtained ethyl 5-(3,4-dimethoxy-5-nitrophenyl)-4-oxazolecarboxylate in the form of yellow crystals of m.p. 109°-110°.

Workup

  1. distillationAfter distillation of the solvent
  2. extractionthe residue is extracted with ethyl acetate/water
  3. customThe crude product obtained
  4. customafter evaporation
  5. customis chromatographed on a 20-fold amount of silica gel with ethyl acetate
  6. customAfter recrystallization from ethyl acetate/hexane there

Sources & evidence

ORD record
ord-a26c95414d90447d8343ba7a884b5c62
Source dataset
uspto-grants-1993_08
Patent number
US05236952

Reaction notes

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