Reaktion #310949

Reaktionsgleichung

methyl-α-bromo-m-toluate

triphenyl phosphine

→

m-Carbomethoxybenzyltriphenyl phosphonium bromide

Lösungsmittel

benzene

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwas refluxed for 2 hr
2. 2
   Sonstigethe phosphonium bromide started precipitating from the solution
3. 3
   Filtrationthe solid was filtered
4. 4
   Waschenwashed with plenty of petroleum ether
5. 5
   Sonstigedried
6. 6
   Sonstigeabsorption of 1720 cm-1 (COOCH3)

Vorschrift

A mixture of 230 g (1.0 mole) of methyl-α-bromo-m-toluate and 300 g (1.2 mole) of triphenyl phosphine in 1 l of dry benzene was refluxed for 2 hr. After 15 minutes, the phosphonium bromide started precipitating from the solution. After cooling the flask to room temperature, the solid was filtered, washed with plenty of petroleum ether and dried. The yield 487 g was quantitative. m.p. 234°-236° C. The infrared spectrum showed absorption of 1720 cm-1 (COOCH3). NMR (CDCl3) showed 3.8 (S, --COOCH3, 3), 5.5-5.8 (d, --CH2 -P, 2), and 7-8.4 (m, aromatic, 19). Anal. calcd. for C27H24O2P Br: C, 65.98%, H, 4.88%, Br. 16.29%. Found: C, 65.88%, H, 4.82%, Br, 16.49%.

Quelle