Scheme 2
Reagents and Conditions: (
a
) Ethyl bromoacetate, NaH, DMF, N
2
, 0°C, rt,1.5 h; (
b
) KOH, MeOH, reflux, 2 h; (
c
) Ethyl bromoacetate, K
2
CO
3
, MeCN, reflux, 12 h.
