(Hive Addict)
07-27-02 14:42
No 337825
      P2Pol synth.
(Rated as: excellent)

Taken from JACS 2295, 62, 1940


To a grignard reagent prepared from 471 g. of bromobenzene and 74 g. of
magnesium in 1400 cc. of ether was slowly added 180 g of propylene oxide.
After refluxing for twenty hours, the mixture was treated with aqeous ammonium
chloride solution. The crude product, b.p. 90-110 at 4mm, amounted to 280
g. On fractionation in the above-mentioned column there was obtained 244 g.
(60%) of 1-phenyl-2-propanol, b.p. 105-107 ' at 14-15 mm, n20d 1.5196. The
phenyl urethan melted at 88.2-88.8'.


To a solution of 180 g. of phosporus tribromide in 100 cc. of benzen  was
added with cooling 128 g. of 1-phenyl-2-propanol during one hour. The
mixture stood at room temperature for two hours and was then slowly heated
for ten mintes. The benzene layer was washed with water and dried over
calcium chloride. The yield of twice distilled 1-phenyl-2-bromopropane,
b.p. 112.5-114.0 at 20-21 mm, n20d 1.5416 was 118 g. (63%). The same
bromide was obtained in 60% yield by refluxing 1-phenyl-2-propanol
with an excess of 48% hydrobromic acid.

(Stranger / Eraser)
07-28-02 16:09
No 338219
      P2Pol  Bookmark   

If you add catalytic amount of cupprous salt to Grignard reagent before adding propylene oxide, you would afford better yields (i.e. Gazz.Chim.Ital. 1991, 455 - 93% yield m-OMOM-P2Pol).