Trimethyl orthoacetate → 5-Methoxy-2-methylbenzoxazole

HRID 22714

Reaction equation

HRID 22714 reaction equation
[NH2:1][C:2]1[CH:7]=[C:6]([O:8][CH3:9])[CH:5]=[CH:4][C:3]=1[OH:10].[C:11](OC)(OC)(OC)[CH3:12]>>[CH3:9][O:8][C:6]1[CH:5]=[CH:4][C:3]2[O:10][C:11]([CH3:12])=[N:1][C:2]=2[CH:7]=1

Participants

3

Reactant 2

HCID 15050Trimethyl orthoacetateHCID 14191082-Amino-4-methoxyphenol

Product 1

HCID 797595-Methoxy-2-methylbenzoxazole

Procedure

A solution of 2-amino-4-methoxyphenol 17 (8 g, 57.4 mmol) in trimethyl orthoacetate 18 (50 mL) was heated to reflux and allowed to stir for 24 h. The reaction was allowed to cool and the excess 18 was evaporated (in vacuo). The residue was dissolved in ethyl acetate and washed with water. The organic layer was dried over MgSO4 and treated with activated carbon Norit A. The resulting solution was filtered through Celite 521 and evaporated to yield an oil. The oil was chromatographed on silica gel (20% ethyl acetate/hexanes) to yield compound 19 as a light yellow solid. Synthesis of 2-methyl-5-oxiran-2-ylmethoxybenzoxazole (67):

Workup

  1. temperatureto reflux
  2. temperatureto cool
  3. customthe excess 18 was evaporated (in vacuo)
  4. dissolutionThe residue was dissolved in ethyl acetate
  5. washwashed with water
  6. dry with materialThe organic layer was dried over MgSO4
  7. additiontreated with activated carbon Norit A
  8. filtrationThe resulting solution was filtered through Celite 521
  9. customevaporated
  10. customto yield an oil
  11. customThe oil was chromatographed on silica gel (20% ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-c0bca52f05014ddbbde713850ce9dfda
Source dataset
uspto-grants-2005_02
Patent number
US06849632B2

Linked notes

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