Hydrochloric Acid → 6-chloroisochroman

HRID 2292111Notes

Reaction equation

HRID 2292111 reaction equation
[Cl:1][C:2]1[CH:3]=[C:4]([CH2:8][CH2:9][OH:10])[CH:5]=[CH:6][CH:7]=1.[CH2:11]=O.Cl>[OH-].[Na+]>[Cl:1][C:2]1[CH:3]=[C:4]2[C:5](=[CH:6][CH:7]=1)[CH2:11][O:10][CH2:9][CH2:8]2

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 712FormaldehydeHCID 78856m-Chlorophenethylic alcohol

Product 1

HCID 104873246-chloroisochromanYield 88.6%

Reagents, catalysts & solvents 1

HCID 14798Sodium HydroxideSolvent

Procedure

2-(3-Chlorophenyl)ethanol (48.2 g) and paraformaldehyde (10.8 g) were mixed and warmed to 70° on an oil bath. A stream of hydrogen chloride gas was passed vigorously through the suspension for about 7 hr. The reaction mixture was then allowed to stand at room temperature overnight. Aqueous sodium hydroxide solution (100 g/100 ml) was added cautiously to the reaction mixture. After the initial reaction subsided the rest of the alkali solution was run in fast and the resulting mixture was heated at reflux on an oil bath for 2 hr. The reaction mixture was cooled and extracted into ether (3×100 ml). The ether layer was dried (sodium sulphate) and evaporated in vacuo to give the 6-chloroisochroman as an oil (46 g), which was purified by distillation in vacuo (25.1 g, b.pt. 76°-80°/0.6 mmHg), characterised by its nmr spectrum.

Workup

  1. temperaturewarmed to 70° on an oil bath
  2. customAfter the initial reaction
  3. temperaturewas heated
  4. temperatureat reflux on an oil bath for 2 hr
  5. temperatureThe reaction mixture was cooled
  6. extractionextracted into ether (3×100 ml)
  7. dry with materialThe ether layer was dried (sodium sulphate)
  8. customevaporated in vacuo

Sources & evidence

ORD record
ord-c09264493dc04ee4b667ea59f3df55dd
Source dataset
uspto-grants-1989_01
Patent number
US04801593

Reaction notes

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