
Cheap and easy method of aminoalcohols production - for example phenyl-
propanolamine, pseudo-ephedrine and so on, (and ring methoxylated too!)

Preparation of PPA: 

Place in 1 l RB flask 37 ml (35 g) propenylbenzene (bp 69°C at 13 mmHg),
then 250 ml of DMSO, add 15 ml H2O, and with stirring, add 106 g of
N-bromosuccinimide in small portions during 15 min. A yellow color appears
when NBS is added, and by the time the addition is complete, the color is
bright-orange. During the addition temp rose up to 50 C. Stir another 15
min, then pour into 1 l of cold water and 3-5 times extract with 100-ml
portions of ether. The combined etheral extracts washed water, then NaCl
soln, extract dried over MgSO4 and ether was distilled off. Obtained 70 g
of yellow oil PhCH(OH)CH(Br)CH3. Yield almost quantitative. Ref: Organic
Syntheses, vol 59, p.16. 

Dissolve this oil in 100 ml of methanol. Saturate 400 ml of methanol with
ammonia at -10C (bubble ammonia until volume grows to 50% - up to 550-600
ml). Mix methanolic soln of bromohydrine with ammonia soln, place it in
sealed bomb and heat at 110-120°C 4-5 hrs. After cooling open it carefully
(ammonia evolution!) poll in 1 l glass (carefull, please - mixture foamy as
freshly-opened champagne) and allow main quantities of ammonia fly out at
slowly heated water bath. Distill of methanol and obtained semi-cryst oil
dissolve in 300 ml of 20% HCl. Wash milky soln twice with hexane, basify
and extract PPA with methylene chloride (3x100 portions). Dry with NaSO4,
and remove solvent. Result - about 42 g of oil, cryst on chilling with mp
53-55C. Conversion of isopropenylbenzene - PPA is 92%. Not bad, I think.
 
