Reaktion #4829

Reaktionsgleichung

p-Methoxyphenyltrichlorovinyl carbinol

sulfuric acid methanol

hydrogen chloride

→

z-methyl-2-chloro-3-(4'-methoxyphenyl)propenoate

Ausbeute 99.0%

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturat reflux (100° C.-106° C.) for 7 minutes
2. 2
   workup.WAITceases after this period
3. 3
   TemperaturThe solution is cooled
4. 4
   Extraktionfollowed by extraction twice with 20 ml of methylene chloride each time
5. 5
   TrocknenThe organic phase is dried over MgSO4
6. 6
   Filtrationfiltered
7. 7
   Sonstigerotary evaporated

Vorschrift

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.

Quelle