Ethyl 8-methoxy-5-nitrochroman-3-carboxylate → HCID 22464172, compound

HRID 1934820Notes

Reaction equation

HRID 1934820 reaction equation
C([O:3][C:4]([CH:6]1[CH2:11][C:10]2[C:12]([N+:18]([O-:20])=[O:19])=[CH:13][CH:14]=[C:15]([O:16][CH3:17])[C:9]=2[O:8][CH2:7]1)=[O:5])C>C(O)C.[OH-].[Na+]>[CH3:17][O:16][C:15]1[C:9]2[O:8][CH2:7][CH:6]([C:4]([OH:5])=[O:3])[CH2:11][C:10]=2[C:12]([N+:18]([O-:20])=[O:19])=[CH:13][CH:14]=1

Participants

4

Reactant 1

HCID 18739724Ethyl 8-methoxy-5-nitrochroman-3-carboxylate

Product 1

HCID 22464172HCID 22464172, compoundYield 94%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 14798Sodium HydroxideSolvent

Procedure

A mixture of 8-methoxy-5-nitro-3,4-dihydro-2H-1-benzopyran-3-carboxylic acid ethyl ester (5.8 g, 21 mmol) in ethanol (150 mL) and 2 M NaOH (15 mL) was heated to reflux for 30 min. The solvent was evaporated in vacuo the residue dissolved in water. Acidification to pH 2 and extraction with ethyl acetate followed by evaporation of the solvent in vacuo gave 4.9 g (94 % yield) of the title compound: mp 181-183° C.; EIMS (70 eV) m/z (relative intensity) 253 (55, M+).

Workup

  1. temperaturewas heated
  2. temperatureto reflux for 30 min
  3. customThe solvent was evaporated in vacuo the residue
  4. dissolutiondissolved in water
  5. extractionAcidification to pH 2 and extraction with ethyl acetate
  6. customfollowed by evaporation of the solvent in vacuo

Sources & evidence

ORD record
ord-704352eed84a4a36a89291f5a5ea6453
Source dataset
uspto-grants-2002_05
Patent number
US06384225B1

Reaction notes

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