Ethanol → ethyl 3,4-dihydro-6-nitro-2H-1-benzopyran-2-carboxylate

HRID 1906891Notes

Reaction equation

HRID 1906891 reaction equation
[N+:1]([C:4]1[CH:5]=[CH:6][C:7]2[O:12][CH:11]([C:13]([OH:15])=[O:14])[CH2:10][CH2:9][C:8]=2[CH:16]=1)([O-:3])=[O:2].S(=O)(=O)(O)O.[CH2:22](O)[CH3:23]>>[N+:1]([C:4]1[CH:5]=[CH:6][C:7]2[O:12][CH:11]([C:13]([O:15][CH2:22][CH3:23])=[O:14])[CH2:10][CH2:9][C:8]=2[CH:16]=1)([O-:3])=[O:2]

Participants

4

Reactant 3

HCID 702EthanolHCID 1118Sulfuric AcidHCID 22177067HCID 22177067, compound

Product 1

HCID 20211055ethyl 3,4-dihydro-6-nitro-2H-1-benzopyran-2-carboxylateYield 95%

Procedure

A mixture of 60 parts of 3,4-dihydro-6-nitro-2H-1-benzopyran-2-carboxylic acid, 480 parts of ethanol and 5.52 parts of concentrate sulfuric acid was stirred for 2 hours at reflux temperature. The reaction mixture was evaporated. The residue was crystallized from 2,2'-oxybispropane (activated charcoal). The product was filtered off and dried, yielding 65 parts (95%) of ethyl 3,4-dihydro-6-nitro-2H-1-benzopyran-2-carboxylate; mp. 80.8° C. (intermediate 23).

Workup

  1. temperatureat reflux temperature
  2. customThe reaction mixture was evaporated
  3. customThe residue was crystallized from 2,2'-oxybispropane (activated charcoal)
  4. filtrationThe product was filtered off
  5. customdried

Sources & evidence

ORD record
ord-227474fce6944a95885b0aac321ab9e8
Source dataset
uspto-grants-1987_03
Patent number
US04654362

Reaction notes

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