Sulfuric Acid → Methyl 4-amino-5-chloro-2,3-dihydrobenzofuran-7-carboxylate

HRID 1459458Notes

Reaction equation

HRID 1459458 reaction equation
S(=O)(=O)(O)O.[NH2:6][C:7]1[C:12]2[CH2:13][CH2:14][O:15][C:11]=2[C:10]([C:16]([OH:18])=[O:17])=[CH:9][C:8]=1[Cl:19].[CH3:20]O.N>CO>[NH2:6][C:7]1[C:12]2[CH2:13][CH2:14][O:15][C:11]=2[C:10]([C:16]([O:18][CH3:20])=[O:17])=[CH:9][C:8]=1[Cl:19]

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 106324014-Amino-5-chloro-2,3-dihydrobenzofuran-7-carboxylic acidHCID 21705897Ammonia methanol

Product 1

HCID 54393661Methyl 4-amino-5-chloro-2,3-dihydrobenzofuran-7-carboxylateYield 81%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

Sulfuric acid (18 ml) was added dropwise to cooled methanol (90 ml). 4-Amino-5-chloro-2,3-dihydro-7-benzofurancarboxylic acid (20 g) was added to the mixture which was subsequently stirred and refluxed for 3 hours. The reaction mixture was cooled and alkalized with CH3OH/NH3. The solvent was evaporated and the residue stirred in water. The precipitate was filtered off and washed with water and DIPE. The remaining solid was dried, yielding 17.2 g (81%) of methyl 4-amino-5-chloro-2,3-di-hydro-7-benzofurancarboxylate (intermediate 1; mp. 135.4° C.).

Workup

  1. temperaturerefluxed for 3 hours
  2. temperatureThe reaction mixture was cooled
  3. customThe solvent was evaporated
  4. stirringthe residue stirred in water
  5. filtrationThe precipitate was filtered off
  6. washwashed with water and DIPE
  7. customThe remaining solid was dried

Sources & evidence

ORD record
ord-d314552f3561435091baf9e2e889820b
Source dataset
uspto-grants-1998_12
Patent number
US05854261

Reaction notes

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