Nitric Acid → 5-Chloro-7-nitro-2,3-dihydro-1-benzofuran

HRID 374541

Reaction equation

HRID 374541 reaction equation
S(=O)(=O)(O)O.[Cl:6][C:7]1[CH:8]=[CH:9][C:10]2[O:14][CH2:13][CH2:12][C:11]=2[CH:15]=1.[N+:16]([O-])([OH:18])=[O:17]>O>[Cl:6][C:7]1[CH:8]=[C:9]([N+:16]([O-:18])=[O:17])[C:10]2[O:14][CH2:13][CH2:12][C:11]=2[CH:15]=1

Participants

5

Reactant 3

HCID 944Nitric AcidHCID 1118Sulfuric AcidHCID 5929645-Chloro-2,3-dihydro-1-benzofuran

Product 1

HCID 189972445-Chloro-7-nitro-2,3-dihydro-1-benzofuranYield 40.5%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Conditions

Temperature
0 °C

Procedure

To a stirred and cooled mixture of 32 ml of sulfuric acid and 14 ml of water there were added 17 g of 2,3-dihydro-5-chlorobenzofuran, while keeping the temperature at 25° C. After cooling to 0° C. there were added dropwise 14 ml of nitric acid. Stirring and cooling at 0° C. was continued for 44 hours. The reaction mixture was diluted with water (temp. <10° C.) and stirred for 15 min. The precipitate was filtered off, washed with water and recrystallized from a mixture of ethyl acetate and hexane (30:70), yielding 8.9 g (40.5%) of 5-chloro-2,3-dihydro-7-nitrobenzofuran (interm. 3).

Workup

  1. temperaturecooled
  2. customat 25° C
  3. stirringStirring
  4. temperaturecooling at 0° C.
  5. stirringstirred for 15 min
  6. filtrationThe precipitate was filtered off
  7. washwashed with water
  8. customrecrystallized from a mixture of ethyl acetate and hexane (30:70)

Sources & evidence

ORD record
ord-417de0039c7b4e3f9ac70af45c0a5b10
Source dataset
uspto-grants-1996_01
Patent number
US05480912

Linked notes

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