Diphosgene → 5-Chloro-3-methyl isatoic anhydride

HRID 475470Notes

Reaction equation

HRID 475470 reaction equation
[NH2:1][C:2]1[C:10]([CH3:11])=[CH:9][C:8]([Cl:12])=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].Cl[C:14](OC(Cl)(Cl)Cl)=[O:15]>O1CCOCC1>[Cl:12][C:8]1[CH:9]=[C:10]([CH3:11])[C:2]2[NH:1][C:14](=[O:15])[O:5][C:4](=[O:6])[C:3]=2[CH:7]=1

Participants

4

Reactant 2

HCID 10426DiphosgeneHCID 116440442-Amino-5-chloro-3-methylbenzoic acid

Product 1

HCID 115502595-Chloro-3-methyl isatoic anhydride

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Conditions

Temperature
42 °C

Procedure

To a suspension of 2-amino-3-methyl-5-chlorobenzoic acid (i.e. product of Example 6, Step A) (97 g, 520 mmol) stirred, in dry dioxane (750 mL) at room temperature, trichloromethyl chloroformate (63 g, 320 mmol) was added dropwise. The reaction mixture exothermically warmed slowly to 42° C., and the solid almost completely dissolved before a thick suspension formed again. After the suspension was stirred at ambient temperature for 2.5 hours, the title compound was isolated by filtration, washed with ethyl ether, and dried to yield the title product compound, obtained as a white solid (98 g). 1H NMR (DMSO-d6) δ 2.3 (s, 3H), 7.70 (s, 1H), 7.75 (s, 1H), 11.2 (s, 1H).

Workup

  1. dissolutionthe solid almost completely dissolved before a thick suspension
  2. customformed again

Sources & evidence

ORD record
ord-71f81ca5afcb460a8ee03d0c130e609a
Source dataset
uspto-grants-2014_01
Patent number
US08637552B2

Reaction notes

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