Diphosgene → 8-methyl-2,4-dihydro-1H-3,1-benzoxazine-2,4-dione

HRID 475456Notes

Reaction equation

HRID 475456 reaction equation
[NH2:1][C:2]1[C:10]([CH3:11])=[CH:9][CH:8]=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].Cl[C:13](OC(Cl)(Cl)Cl)=[O:14]>O1CCOCC1>[CH3:11][C:10]1[C:2]2[NH:1][C:13](=[O:14])[O:5][C:4](=[O:6])[C:3]=2[CH:7]=[CH:8][CH:9]=1

Participants

4

Reactant 2

HCID 10426DiphosgeneHCID 781012-Amino-3-methylbenzoic acid

Product 1

HCID 27598708-methyl-2,4-dihydro-1H-3,1-benzoxazine-2,4-dione

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent2×

Procedure

To a solution of 2-amino-3-methylbenzoic acid (6 g) in dry 1,4-dioxane (50 mL) was added dropwise a solution of trichloromethyl chloroformate (8 mL) in dry 1,4-dioxane (25 mL), with ice-water cooling to keep the reaction temperature below 25° C. A white precipitate began to form during the addition. The reaction mixture was stirred at room temperature overnight. The precipitated solids were removed by filtration and washed with 1,4-dioxane (2×20 mL) and hexane (2×15 mL) and air-dried to yield 6.51 g of off-white solid.

Workup

  1. customthe reaction temperature below 25° C
  2. customto form during the addition
  3. customThe precipitated solids were removed by filtration
  4. washwashed with 1,4-dioxane (2×20 mL) and hexane (2×15 mL)
  5. customair-dried

Sources & evidence

ORD record
ord-e4681c1e2c774b58b94b7424d7322f84
Source dataset
uspto-grants-2014_01
Patent number
US08637552B2

Reaction notes

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