Paraldehyde → 1,4-Benzodioxin

HRID 1638504Notes

Reaction equation

HRID 1638504 reaction equation
CC1O[CH:6]([CH3:8])[O:5][CH:4]([CH3:9])O1.[OH2:10].[C:11]1(C)C=C[C:14](S(O)(=O)=O)=[CH:13][CH:12]=1>O1CCOCC1>[O:5]1[C:4]2[CH:9]=[CH:11][CH:12]=[CH:13][C:14]=2[O:10][CH:8]=[CH:6]1

Participants

4

Reactant 2

HCID 31264ParaldehydeHCID 521998p-Toluenesulfonic acid monohydrate

Product 1

HCID 1360711,4-BenzodioxinYield 745.5%

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Procedure

Reaction of 3,5-(1,1-dimethylethyl)-2-hydroxybenzenemethanol (7.03 g, 0.03 mol), paraldehyde (13.2, 0.3 mol), p-dioxane (150 mL) and p-toluenesulfonic acid hydrate (0.57 g, 0.003 mol) as described in Example 4, provided after distillation 4.12 g (52% yield, GLC purity 99%), of 6,8-(1,1-dimethylethyl)-2-methyl-4H-1,3-benzodioxin. Crystallization from methanol provided 3.0 g of pure benzodioxin, mp 59°-61° C.; 1H-NMR (CDCl3)δ1.20 (9H, s), 1.30 (9H, s), 1.50 (3H, d, J=5 Hz), 4.83 (2H, dd, J=5 and 14 Hz), 5.10 (1H, q, J=6 Hz), 6.72 (1H, d, J=2 Hz), 7.10 (1H, d, J=2 Hz); IR (CDCl3)λmax 2955, 1490, 1455, 1410 cm-1 ; MS m/e 262, 218, 203, 177, 161; UVλmax (ethanol) 224 nm (ε=4650), 280 nm (ε=1190).

Workup

  1. customprovided
  2. distillationafter distillation 4.12 g (52% yield, GLC purity 99%)
  3. customCrystallization from methanol

Sources & evidence

ORD record
ord-5ca64384393742c4b2509855fd88fdb1
Source dataset
uspto-grants-1989_11
Patent number
US04880775

Reaction notes

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