Hydrochloric Acid → 6-Chloro-5-fluoroindolin-2-one

HRID 374282

Reaction equation

HRID 374282 reaction equation
[NH2:1][C:2]1[CH:7]=[C:6]([Cl:8])[C:5]([F:9])=[CH:4][C:3]=1[CH2:10][C:11]([O:13]C)=O.O.Cl>C(Cl)Cl.C(O)(=O)C>[F:9][C:5]1[CH:4]=[C:3]2[C:2](=[CH:7][C:6]=1[Cl:8])[NH:1][C:11](=[O:13])[CH2:10]2

Participants

6

Reactant 3

HCID 313Hydrochloric Acid3×HCID 962WaterHCID 10900080Methyl (2-amino-4-chloro-5-fluorophenyl)acetate2×

Product 1

HCID 97940836-Chloro-5-fluoroindolin-2-one

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolvent3×HCID 6344DichloromethaneSolvent2×

Procedure

Compound (III) is obtained by cyclizing (II) with an acid as shown in step [b] of Scheme 1. Compound (II) is dissolved in a mixture of an acid and a cosolvent, preferably the acid is glacial acetic acid in which instance the preferred cosolvent is water or the acid is hydrochloric acid in which instance the preferred cosolvent is methylene chloride. With acetic acid the ratio of the acid and cosolvent mixture ranges from 2:1 to pure acetic acid respectively, the preferred ratio being 6:1. With HCl, much less acid is required, preferably 1:4 3N HCl to CH2Cl2. Once compound (II) is dissolved, the reaction mixture is stirred at ambient temperature for from 6 to 7 hours to produce 5-fluoro-6-chlorooxindole (III). Compound (III) is readily purified by recrystallization from ethyl acetate to yield an off-white solid.

Sources & evidence

ORD record
ord-f6e926db4fe440bcbe8c2c714bdbecf2
Source dataset
uspto-grants-1992_11
Patent number
US05166401

Linked notes

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