p-Toluenesulfonic acid → 2-(1,1-Dimethoxyethyl)thiazole

HRID 1178206Notes

Reaction equation

HRID 1178206 reaction equation
[S:1]1[CH:5]=[CH:4][N:3]=[C:2]1[C:6](=[O:8])[CH3:7].[CH:9](OC)(OC)[O:10]C.[C:16]1(C)C=CC(S(O)(=O)=O)=CC=1>CO>[CH3:16][O:8][C:6]([C:2]1[S:1][CH:5]=[CH:4][N:3]=1)([O:10][CH3:9])[CH3:7]

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 9005Trimethyl orthoformateHCID 5201082-Acetylthiazole

Product 1

HCID 110739802-(1,1-Dimethoxyethyl)thiazole

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
50 °C

Procedure

To a solution of 1-Thiazol-2-yl-ethanone (7 g) in dry methanol (100 ml) was added trimethyl orthoformate (35 ml) and p-toluenesulfonic acid (10 g) and the resulting mixture was heated at 50° C. for 12 hours. The mixture was cooled to ambient and concentrated, partitioned between saturated sodium bicarbonate and diethyl ether (100 ml). The organic phase was removed and washed with saturated sodium bicarbonate and brine, dried (magnesium sulfate), filtered and concentrated to afford the sub-title compound as crude product. The product could be further purified if necessary by flash chromatography (20% ethyl acetate/petroleum ether) to afford the sub-title compound in quantitative yield as yellow oil (9.5 g); 1H NMR (400 Mhz, CDCl3) δ 1.75 (3H, s), 3.25 (6H, s), 7.3 (1H, s), 7.85 (1H, s); MS (ES+) 174.1 (M+1).

Workup

  1. temperatureThe mixture was cooled to ambient and
  2. concentrationconcentrated
  3. custompartitioned between saturated sodium bicarbonate and diethyl ether (100 ml)
  4. customThe organic phase was removed
  5. washwashed with saturated sodium bicarbonate and brine
  6. dry with materialdried (magnesium sulfate)
  7. filtrationfiltered
  8. concentrationconcentrated

Sources & evidence

ORD record
ord-b5d2a21eba234f47b88bdf17c93bb46c
Source dataset
uspto-grants-2007_10
Patent number
US07276502B2

Reaction notes

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