2-Amino-3-methylbenzoic acid → 8-methyl-2,4-dihydro-1H-3,1-benzoxazine-2,4-dione

HRID 723250Notes

Reaction equation

HRID 723250 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].C(N(C(C)C)CC)(C)C.Cl[C:22](Cl)([O:24]C(=O)OC(Cl)(Cl)Cl)Cl>C1COCC1.ClCCl>[CH3:11][C:10]1[C:2]2[NH:1][C:22](=[O:24])[O:5][C:4](=[O:6])[C:3]=2[CH:7]=[CH:8][CH:9]=1

Participants

6

Reactant 3

HCID 781012-Amino-3-methylbenzoic acidHCID 81531DiisopropylethylamineHCID 94429Triphosgene

Product 1

HCID 27598708-methyl-2,4-dihydro-1H-3,1-benzoxazine-2,4-dioneYield 282.8%

Reagents, catalysts & solvents 2

HCID 6344DichloromethaneSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 2-amino-3-methylbenzoic acid (9.07 g, 60 mmol) in THF (60 mL) was added simultaneously diisopropylethylamine (20.9 mL) and a solution of triphosgene (5.94 g, 20 mmol) in dichloromethane (60 mL) over 30 minutes period. After the addition was completed, the mixture stirred at ambient temperature for 16 hours. Solid was filtered and washed with ether (2×100 mL) and H2O (3×50 mL), and dried in high vacuum to afford the title compound (10.02 g, 94% yield) as a white solid. 1H NMR (DMSO) δ 11.02 (s, 1H), 7.76 (d, 1H, J=7.7 Hz), 7.57 (d, 1H, J=7.5 Hz), 7.17–7.13 (m, 1H), 2.32 (s, 3H).

Workup

  1. additionAfter the addition
  2. filtrationSolid was filtered
  3. washwashed with ether (2×100 mL) and H2O (3×50 mL)
  4. customdried in high vacuum

Sources & evidence

ORD record
ord-f8db60f92a624bc595b57d0b55db9a20
Source dataset
uspto-grants-2006_11
Patent number
US07138530B2

Reaction notes

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