Methyl 7-chloro-2,3-dihydro-8-methoxy-1,4-benzodioxin-5-carboxylate → 7-Chloro-2,3-dihydro-8-methoxy-1,4-benzodioxin-5-carboxylic acid

HRID 1868356Notes

Reaction equation

HRID 1868356 reaction equation
[Cl:1][C:2]1[CH:3]=[C:4]([C:14]([O:16]C)=[O:15])[C:5]2[O:10][CH2:9][CH2:8][O:7][C:6]=2[C:11]=1[O:12][CH3:13]>[OH-].[Na+]>[Cl:1][C:2]1[CH:3]=[C:4]([C:14]([OH:16])=[O:15])[C:5]2[O:10][CH2:9][CH2:8][O:7][C:6]=2[C:11]=1[O:12][CH3:13]

Participants

3

Reactant 1

HCID 11565132Methyl 7-chloro-2,3-dihydro-8-methoxy-1,4-benzodioxin-5-carboxylate

Product 1

HCID 115939517-Chloro-2,3-dihydro-8-methoxy-1,4-benzodioxin-5-carboxylic acidYield 2.6%

Reagents, catalysts & solvents 1

HCID 14798Sodium HydroxideSolvent

Procedure

A mixture of intermediate (2) (0.138 mol) in a 2N NaOH solution (500 ml) was stirred and refluxed for 1 hour, then cooled and washed with DCM. The mixture was separated into its layers. The aqueous layer was acidified with a concentrated HCl solution until pH=2. The solid was filtered off, washed with water and dried in vacuo. A part (2.5 g) of this fraction was crystallized from methanol. The precipitate was filtered off and dried, yielding 0.88 g of 7-chloro-2,3-dihydro-8-methoxy-1,4-benzodioxin-5-carboxylic acid (intermediate 3, mp. 172° C.).

Workup

  1. temperaturerefluxed for 1 hour
  2. temperaturecooled
  3. washwashed with DCM
  4. customThe mixture was separated into its layers
  5. filtrationThe solid was filtered off
  6. washwashed with water
  7. customdried in vacuo
  8. customA part (2.5 g) of this fraction was crystallized from methanol
  9. filtrationThe precipitate was filtered off
  10. customdried

Sources & evidence

ORD record
ord-331ee86488bb45b8aa2398f3db7e4946
Source dataset
uspto-grants-2009_12
Patent number
US07635706B2

Reaction notes

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