Phosgene → 6-Methyl-2H-thieno[2,3-d][1,3]oxazine-2,4(1H)-dione

HRID 1454221Notes

Reaction equation

HRID 1454221 reaction equation
[NH2:1][C:2]1[S:3][C:4]([CH3:10])=[CH:5][C:6]=1[C:7]([OH:9])=[O:8].[O:11]1CCOC[CH2:12]1.C(Cl)(Cl)=O>C1(C)C=CC=CC=1>[CH3:10][C:4]1[S:3][C:2]2[NH:1][C:12](=[O:11])[O:8][C:7](=[O:9])[C:6]=2[CH:5]=1

Participants

5

Reactant 3

HCID 6371PhosgeneHCID 312751,4-DioxaneHCID 219315912-Amino-5-methylthiophene-3-carboxylic acid

Product 1

HCID 138498796-Methyl-2H-thieno[2,3-d][1,3]oxazine-2,4(1H)-dioneYield 100%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Conditions

Temperature
5 °C

Procedure

step 2—A suspension of 60b (4.0 g, 25.5 mmol) and dioxane (65 mL) was cooled to 5° C. Phosgene (22.5 mL of a 20% solution in toluene, 45.9 mmol) was added dropwise through a septum. The flask was equipped with a condenser and the mixture was refluxed for 4 h. After cooling the solvents were evaporated in vacuo to afford 5.0 g (100%) of 6-methyl-1H-thieno[2,3-d][1,3]oxazine-2,4-dione (61a) which was used without purification: ms [M−H]=182.

Workup

  1. customThe flask was equipped with a condenser
  2. temperaturethe mixture was refluxed for 4 h
  3. temperatureAfter cooling the solvents
  4. customwere evaporated in vacuo

Sources & evidence

ORD record
ord-83d333c553f744bfab35b5f66825a04e
Source dataset
uspto-grants-2009_01
Patent number
US07479489B2

Reaction notes

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