Hydrochloric Acid → 6-Hydroxy-2,5,7,8-tetramethylchroman-2-acetic acid

HRID 1701297Notes

Reaction equation

HRID 1701297 reaction equation
[CH3:1]/[C:2](=[CH:6]/[CH2:7][C:8]1[C:13]([O:14]C(=O)C)=[C:12]([CH3:18])[C:11]([CH3:19])=[C:10]([O:20]C(=O)C)[C:9]=1[CH3:24])/[CH2:3][C:4]#N.C=C(CCC1C(OC(=O)C)=C(C)C(C)=C(OC(=O)C)C=1C)CC#N.[OH-:49].[K+].Cl.[OH2:52]>C(O)CO>[OH:20][C:10]1[C:11]([CH3:19])=[C:12]([CH3:18])[C:13]2[O:14][C:2]([CH2:3][C:4]([OH:52])=[O:49])([CH3:1])[CH2:6][CH2:7][C:8]=2[C:9]=1[CH3:24]

Participants

7

Reactant 5

HCID 313Hydrochloric AcidHCID 962Water2×HCID 14797Potassium HydroxideHCID 203337993-Methylene-5-(2,4,5-trimethyl-3,6-diacetyloxy-phenyl)pentanenitrileHCID 20333801Z-3-methyl-5-(2,4,5-trimethyl-3,6-diacetyloxyphenyl)-3-pentenenitrile

Product 1

HCID 55926-Hydroxy-2,5,7,8-tetramethylchroman-2-acetic acidYield 84%

Reagents, catalysts & solvents 1

HCID 174Ethylene GlycolSolvent

Procedure

A mixture of 623 mg (1.89 mmoles) of the mixture of E-and Z-3-methyl-5-(2,4,5-trimethyl-3,6-diacetyloxyphenyl)-3-pentenenitrile and 3-methylene-5-(2,4,5-trimethyl-3,6-diacetyloxy-phenyl)pentanenitrile, 498 mg (7.70 mmoles) of 85% KOH, 5 ml of ethylene glycol and 0.5 ml of water was stirred and refluxed for 36 hr. The reaction mixture was cooled to room temperature, then poured into water. The pH of the solution was adjusted to 8 with 1 N aqueous HCl and the resulting mixture was extracted with two portions of ether (the extracts were discarded). The aqueous phase was acidified with 3 N aqueous HCl and worked-up with ether in the usual manner giving 421 mg (84%) of rac.-(6-hydroxy-3,4-dihydro-2,5,7,8-tetramethyl-2H-1-benzopyran-2-yl)acetic acid as a tan solid, mp 168°-170°.

Workup

  1. temperaturerefluxed for 36 hr
  2. extractionthe resulting mixture was extracted with two portions of ether (the extracts

Sources & evidence

ORD record
ord-f13a28d651b5499d9dfcc54d10a15490
Source dataset
uspto-grants-1980_03
Patent number
US04192816

Reaction notes

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