Hydrochloric Acid → 4,4-Dimethyl-7-(3-methyloctan-2-yl)-1,4-dihydro-3H-thieno[3,4-c][1]benzopyran-9-ol

HRID 1579101Notes

Reaction equation

HRID 1579101 reaction equation
[OH:1][C:2]1C2C3CSCC=3C(=O)OC=2[CH:5]=[C:4]([CH:16]([CH:18]([CH3:24])[CH2:19][CH2:20][CH2:21][CH2:22][CH3:23])[CH3:17])[CH:3]=1.Br[CH3:26].[Mg].Cl.[C:29]1(C)[CH:34]=[CH:33][C:32]([S:35](O)(=O)=O)=CC=1.[CH3:40][CH2:41][O:42][CH2:43][CH3:44]>C1C=CC=CC=1>[CH3:40][C:41]1([CH3:26])[C:33]2[CH2:32][S:35][CH2:29][C:34]=2[C:44]2[C:2]([OH:1])=[CH:3][C:4]([CH:16]([CH:18]([CH3:24])[CH2:19][CH2:20][CH2:21][CH2:22][CH3:23])[CH3:17])=[CH:5][C:43]=2[O:42]1

Participants

8

Reactant 6

HCID 313Hydrochloric AcidHCID 3283Diethyl EtherHCID 6101p-Toluenesulfonic acidHCID 6323Methyl BromideHCID 5462224MagnesiumHCID 21433934HCID 21433934, compound

Product 1

HCID 30449214,4-Dimethyl-7-(3-methyloctan-2-yl)-1,4-dihydro-3H-thieno[3,4-c][1]benzopyran-9-olYield 42%

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent2×

Conditions

Temperature
45 °C

Procedure

A suspension of 6.0 g. (0.017 mole) of the pyrone of Example 26, part B, in 150 ml. of benzene was added to a Grignard reagent prepared by adding bromomethane to 8.47 g. (0.36 mole) of magnesium turnings in 100 ml. of ether. The mixture was heated at 45°C for 24 hours and then decomposed by the addition of dilute hydrochloric acid. The organic layer was separated, washed with water, dried over sodium sulfate and evaporated to give a gummy residue. This material, as the triol, was dissolved in benzene and refluxed for 3 hours with a few crystals of p-toluenesulfonic acid. The benzene solution was washed, dried and evaporated to give a dark gum which was chromatographed using Florisil (60-100 mesh) and graded ether/petroleum ether solvent mixtures. 2.6 g. (42%) of colorless gum was obtained. The material was shown to be pure by TLC (20% ether/petroleum ether) and exhibited λmaxEtOH 284 mμ (logε 4.157). The IR and NMR spectra were in agreement with the proposed structure.

Workup

  1. additionA suspension of 6.0 g
  2. customprepared
  3. customThe organic layer was separated
  4. washwashed with water
  5. dry with materialdried over sodium sulfate
  6. customevaporated
  7. customto give a gummy residue
  8. washThe benzene solution was washed
  9. customdried
  10. customevaporated
  11. customto give a dark gum which
  12. customwas chromatographed

Sources & evidence

ORD record
ord-70993ac7c5bb4813ba3c1a06eb184b38
Source dataset
uspto-grants-1976_02
Patent number
US03940421

Reaction notes

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