Reaction #50992

Reaction equation

2-amino-4-methoxyphenol

trimethyl orthoacetate

→

compound 19

5-methoxy-2-methyl-benzoxazole

Conditions

Workup

1. 1
   Temperatureto reflux
2. 2
   Temperatureto cool
3. 3
   Otherthe excess 18 was evaporated (in vacuo)
4. 4
   workup.DISSOLUTIONThe residue was dissolved in ethyl acetate
5. 5
   Washwashed with water
6. 6
   DryingThe organic layer was dried over MgSO4
7. 7
   workup.ADDITIONtreated with activated carbon Norit A
8. 8
   FiltrationThe resulting solution was filtered through Celite 521
9. 9
   Otherevaporated
10. 10
    Otherto yield an oil
11. 11
    OtherThe oil was chromatographed on silica gel (20% ethyl acetate/hexanes)

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):

Source