Acetic Acid → 2,2-dimethyl-6-nitro-2H-1-benzopyran-4-carboxylic acid

HRID 36085Notes

Reaction equation

HRID 36085 reaction equation
C(C1[C:8]2[CH:9]=[C:10]([N+:13]([O-:15])=[O:14])[CH:11]=[CH:12][C:7]=2[O:6][C:5]([CH3:17])([CH3:16])[CH:4]=1)#N.[C:18]([OH:21])(=[O:20])[CH3:19].S(=O)(=O)(O)O>O>[CH3:16][C:5]1([CH3:17])[CH:4]=[C:19]([C:18]([OH:21])=[O:20])[C:8]2[CH:9]=[C:10]([N+:13]([O-:15])=[O:14])[CH:11]=[CH:12][C:7]=2[O:6]1

Participants

5

Reactant 3

HCID 176Acetic AcidHCID 1118Sulfuric Acid2×HCID 152347484-cyano-2,2-dimethyl-6-nitro-2H-1-benzopyran

Product 1

HCID 152347442,2-dimethyl-6-nitro-2H-1-benzopyran-4-carboxylic acid

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

MS: 230 (M+) ##STR41## A mixture of 13.0 g of 4-cyano-2,2-dimethyl-6-nitro-2H-1-benzopyran, 400 ml of acetic acid, 200 ml of water, and 100 ml of concentrated sulfuric acid was heated at reflux for 1.5 hours. After adding 100 ml of concentrated sulfuric acid, the refluxing was further continued for an additional period of 1 hour. The reaction mixture was poured into ice-water. The thus precipitated crystal was washed with water, dried, and recrystallized from a mixed solvent of acetonitrile and water to obtain 11.9 g of 2,2-dimethyl-6-nitro-2H-1-benzopyran-4-carboxylic acid represented by formula shown below.

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 1.5 hours
  3. washThe thus precipitated crystal was washed with water
  4. customdried
  5. customrecrystallized from a mixed solvent of acetonitrile and water

Sources & evidence

ORD record
ord-0f41f1436ed74e37ae7a9f647bcfa83a
Source dataset
uspto-grants-1995_05
Patent number
US05412117

Reaction notes

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