Hydrochloric Acid → 2,2-Dimethyl-2,3-dihydro-1-benzofuran-7-sulfonyl chloride

HRID 2309321Notes

Reaction equation

HRID 2309321 reaction equation
N([O-])=O.[Na+].N[C:6]1[C:14]2[O:13][C:12]([CH3:16])([CH3:15])[CH2:11][C:10]=2[CH:9]=[CH:8][CH:7]=1.[S:17](=[O:21])(=O)(O)[OH:18].[ClH:22].S(=O)=O>O.ClCCCC.C(O)(=O)C>[CH3:15][C:12]1([CH3:16])[CH2:11][C:10]2[CH:9]=[CH:8][CH:7]=[C:6]([S:17]([Cl:22])(=[O:21])=[O:18])[C:14]=2[O:13]1

Participants

9

Reactant 5

HCID 313Hydrochloric AcidHCID 1118Sulfuric AcidHCID 1119Sulfur DioxideHCID 916972,2-Dimethyl-2,3-dihydro-1-benzofuran-7-amineHCID 23668193Sodium Nitrite

Product 1

HCID 134241792,2-Dimethyl-2,3-dihydro-1-benzofuran-7-sulfonyl chloride

Reagents, catalysts & solvents 3

HCID 176Acetic AcidSolventHCID 962WaterSolvent2×HCID 8005Butyl ChlorideSolvent

Conditions

Temperature
10 °C

Procedure

A diazonium salt was prepared by adding 13.8 g of sodium nitrite to a suspension of 32.6 g of 7-amino-2,3-dihydro-2,2-dimethylbenzofuran and 40 ml of concentrated sulfuric acid in 200 ml water cooled 0° to 5° C. After stirring for about 0.4 hour at 0° to 5° C., the diazonium salt suspension was poured in one portion into a mixture consisting of 170 ml of acetic acid, 40 ml of concentrated hydrochloric acid, 17 g of cupric chloride dihydrate and 30 ml of sulfur dioxide and cooled at 10° C. by an ice-water bath. The mixture was stirred about 1 hour at 15° to 25° C. Then 400 ml of 1-chlorobutane and 200 ml of water was added and the mixture was stirred and heated at 35° C. for 5 hours. After cooling to room temperature, the organic layer was separated, washed with saturated aqueous NaHCO3 and water, and dried over sodium sulfate for 0.5 hour. The solvent was evaporated under reduced pressure at less than 45° C. to give 26 g of crude 2,3-dihydro-2,2-dimethyl-7-benzofuransulfonyl chloride as an oil.

Workup

  1. temperaturecooled 0° to 5° C
  2. stirringThe mixture was stirred about 1 hour at 15° to 25° C
  3. stirringthe mixture was stirred
  4. temperatureheated at 35° C. for 5 hours
  5. temperatureAfter cooling to room temperature
  6. customthe organic layer was separated
  7. washwashed with saturated aqueous NaHCO3 and water
  8. dry with materialdried over sodium sulfate for 0.5 hour
  9. customThe solvent was evaporated under reduced pressure at less than 45° C.

Sources & evidence

ORD record
ord-65117ac60df846d5943034af57301baf
Source dataset
uspto-grants-1987_09
Patent number
US04695310

Reaction notes

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