Water → HCID 54483996, compound

HRID 414145Notes

Reaction equation

HRID 414145 reaction equation
[CH2:1]([O:8][C:9]1[C:10]([CH3:26])=[C:11]2[C:16](=[C:17]([CH3:20])[C:18]=1[CH3:19])[O:15][C@@:14]([CH2:22][C:23](O)=[O:24])([CH3:21])[CH2:13][CH2:12]2)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.O.C(Cl)(=O)C([Cl:31])=O>C1(C)C=CC=CC=1>[CH2:1]([O:8][C:9]1[C:10]([CH3:26])=[C:11]2[C:16](=[C:17]([CH3:20])[C:18]=1[CH3:19])[O:15][C@@:14]([CH2:22][C:23]([Cl:31])=[O:24])([CH3:21])[CH2:13][CH2:12]2)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

5

Reactant 3

HCID 962WaterHCID 65578Oxalyl chlorideHCID 14368744HCID 14368744, compound

Product 1

HCID 54483996HCID 54483996, compoundYield 101.2%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Conditions

Temperature
50 °C

Procedure

201.0 g (0.57 mole) of (S)-(6-benzyloxy-2,5,7,8-tetramethylchroman-2-yl)acetic acid was dissolved in 1.0 L toluene and transferred to a 3 L three necked flask equipped with a Dean-Stark trap and condenser, magnetic stirrer and a thermometer connected to a heating mantle. The solution was refluxed 1 hour with no appreciable amount of water collecting in the Dean-Stark trap. This was removed, and the solution was cooled to 50° C. Then a pressure equalizing addition funnel was placed on top and the oxalyl chloride 58.5 mL (0.68 mole, 1.2 equiv.) was added dropwise at about one drop per second. The color became orange, and the temperature increased to about 60° C. as gas evolution began smoothly. The rate of addition was monitored so that gas evolution was not too vigorous. The gas evolved was bubbled through two aqueous sodium hydroxide traps. The slow addition was continued over about 1 hour and then heating was applied with a thermowatch keeping the heat at 60° C. The solution was then condensed on the rotovap, and after pumping off any residual solvent for 2 hours, 215.2 g (>100%) of (S)-(6-benzyloxy-2,5,7,8-tetramethyl chroman-2-yl)acetic acid chloride was obtained (211.45 g theoretical).

Workup

  1. customequipped with a Dean-Stark trap and condenser, magnetic stirrer
  2. customThis was removed
  3. additionaddition funnel
  4. temperaturethe temperature increased to about 60° C. as gas evolution
  5. additionThe rate of addition
  6. customThe gas evolved was bubbled through two aqueous sodium hydroxide traps
  7. additionThe slow addition
  8. temperatureheating
  9. temperatureheat at 60° C
  10. customcondensed on the rotovap
  11. customfor 2 hours

Sources & evidence

ORD record
ord-a8e0a3ffb49b4492bf2f388504520833
Source dataset
uspto-grants-1988_12
Patent number
US04789750

Reaction notes

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