反应详情

p-Methoxyphenyltrichlorovinyl carbinol (2.3 g, 8.6 millimoles) is added to a 40:60 (V/V) solution of sulfuric acid/methanol which is stirred under nitrogen at reflux (100° C.-106° C.) for 7 minutes. Rapid evolution of hydrogen chloride is noted and ceases after this period. The solution is cooled and poured into 40 ml of water, followed by extraction twice with 20 ml of methylene chloride each time. The organic phase is dried over MgSO4, filtered and rotary evaporated giving z-methyl-2-chloro-3-(4'-methoxyphenyl)propenoate (1.92 g, 8.5 millimoles) in 99 percent yield as a light yellow oil which crystallized on standing (M.P.=68° C.-70° C., M.P.LIT1 =67° C.-70° C.): 'H NMR (CDCl3) δ 7.24 (4H, ab quartet), 7.72 (1H, s), 3.76 (3H, s), 3.68 (3H, s); 13C NMR (CDCl3) δ 164.0, 161.1, 136.7, 132.6, 125.4, 119.0, 113.9, 55.2, 53.0.

1. temperatureat reflux (100° C.-106° C.) for 7 minutes
2. waitceases after this period
3. temperatureThe solution is cooled
4. extractionfollowed by extraction twice with 20 ml of methylene chloride each time
5. dry with materialThe organic phase is dried over MgSO4
6. filtrationfiltered
7. customrotary evaporated