Diphosgene → 1H,2H,4H-thieno(3,2-d)(1,3)oxazine-2,4-dione

HRID 902491Notes

Reaction equation

HRID 902491 reaction equation
[NH2:1][C:2]1[CH:6]=[CH:5][S:4][C:3]=1[C:7]([O:9][CH3:10])=[O:8].[OH-].[K+].ClC(OC(Cl)(Cl)Cl)=[O:15]>O>[NH:1]1[C:2]2[CH:6]=[CH:5][S:4][C:3]=2[C:7](=[O:8])[O:9][C:10]1=[O:15]

Participants

5

Reactant 3

HCID 10426DiphosgeneHCID 14797Potassium HydroxideHCID 89652Methyl 3-amino-2-thiophenecarboxylate

Product 1

HCID 27775521H,2H,4H-thieno(3,2-d)(1,3)oxazine-2,4-dioneYield 85%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
90 °C

Procedure

Methyl 3-aminothiophene-2-carboxylate (31.0 g, 0.20 mol) was added to a solution of potassium hydroxide (22.68 g, 0.40 mol) in 1 L water. The solution was heated at 90° C. for 2 hours. The solution was then cooled to 0° C. and trichloromethyl chloroformate (35.7 mL, 0.30 mol) was added slowly, maintaining the temperature between 0° C. and 10° C. The solution was stirred at 0° C. for 4 hours, and then allowed to warm up gradually to room temperature and stirred for another 3 hours. The precipitated solid product was collected by vacuum filtration to give 28.5 g (85% yield) 1H-thieno[3,2-d][1,3]oxazine-2,4-dione. 1H-NMR (DMSO-d6) δ 6.94 (d, J=5.0 Hz, 1H), 8.24 (d, J=5.0 Hz, 1H), 12.26 (b, 1H) ppm; EIMS m/z 170 (M+1).

Workup

  1. temperatureThe solution was then cooled to 0° C.
  2. temperaturemaintaining the temperature between 0° C. and 10° C
  3. temperatureto warm up gradually to room temperature
  4. stirringstirred for another 3 hours
  5. filtrationThe precipitated solid product was collected by vacuum filtration

Sources & evidence

ORD record
ord-90b4f9639144412489119880232ae38c
Source dataset
uspto-grants-2008_04
Patent number
US07365200B2

Reaction notes

Loading…