There is an alternative procedure that uses the weak base K2CO3 (pKa = 10.3) instead of NaOEt (pKa = 15.9); why can a weak base like K2CO3 be used for the phenacetin synthesis, given that Williamson ether syntheses using aliphatic alcohols need to use very powerful bases like sodium hydride or sodium metal (p. 537 of McMurry 8th ed.)?