Potassium Iodide → Ethyl 2-iodooxazole-4-carboxylate

HRID 2092236Notes

Reaction equation

HRID 2092236 reaction equation
N[C:2]1[O:3][CH:4]=[C:5]([C:7]([O:9][CH2:10][CH3:11])=[O:8])[N:6]=1.O.O.C1(C)C=CC(S(O)(=O)=O)=CC=1.N([O-])=O.[Na+].[I-:29].[K+].C(=O)(O)[O-].[Na+].S([O-])([O-])(=O)=S.[Na+].[Na+]>C(#N)C.O>[I:29][C:2]1[O:3][CH:4]=[C:5]([C:7]([O:9][CH2:10][CH3:11])=[O:8])[N:6]=1

Participants

9

Reactant 6

HCID 4875Potassium IodideHCID 24477Sodium ThiosulfateHCID 319549Ethyl 2-amino-1,3-oxazole-4-carboxylateHCID 516892Sodium BicarbonateHCID 23668193Sodium NitriteHCID 86626551p-Toluenesulfonic acid dihydrate

Product 1

HCID 46910517Ethyl 2-iodooxazole-4-carboxylate

Reagents, catalysts & solvents 2

HCID 962WaterSolvent2×HCID 6342AcetonitrileSolvent

Conditions

Temperature
0 °C

Procedure

2.00 g (12.81 mmol) of ethyl 2-amino-1,3-oxazole-4-carboxylate are added to a solution of 8.00 g (38.43 mmol) of p-toluenesulfonic acid dihydrate in 48 ml of acetonitrile. The suspension is cooled to 0° C., and a solution of 1.77 g (25.62 mmol) sodium nitrite and 5.32 g (32.02 mmol) potassium iodide in 7.2 ml of water is then added. The mixture is stirred at 0° C. for 10 min and, after warming to RT, further overnight. The mixture is then diluted with 200 ml of water. By addition of 1 M aqueous sodium bicarbonate solution, the pH is adjusted to 9.24 ml of 2 M sodium thiosulfate solution are then added. The aqueous phase is extracted three times with in each case 30 ml of ethyl acetate. The combined organic phases are dried over magnesium sulfate. After filtration, the solvent is removed on a rotary evaporator. The residue is purified by column chromatography on silica gel 60 (mobile phase gradient: cyclohexane/ethyl acetate 300:1→2:1).

Workup

  1. temperatureafter warming to RT, further overnight
  2. additionare then added
  3. extractionThe aqueous phase is extracted three times with in each case 30 ml of ethyl acetate
  4. dry with materialThe combined organic phases are dried over magnesium sulfate
  5. filtrationAfter filtration
  6. customthe solvent is removed on a rotary evaporator
  7. customThe residue is purified by column chromatography on silica gel 60 (mobile phase gradient: cyclohexane/ethyl acetate 300:1→2:1)

Sources & evidence

ORD record
ord-872f4d74bade44f597cb0fb13d86ae95
Source dataset
uspto-grants-2013_05
Patent number
US08440700B2

Reaction notes

Loading…