تفاعل #7294

معادلة التفاعل

cysteamine hydrochloride

ammonia

benzyl bromide

→

S-Benzylcysteamine

المردود 86.0%

المذيبات

methanol

ظروف التفاعل

المعالجة

1. 1
   ترشيحthe formed precipitate of S-dibenzylcysteamine was collected by filtration
2. 2
   استخلاصThe product was extracted with ether (3×100 mL)
3. 3
   غسيلthe organic phase was successively washed with brine (2×100 mL)
4. 4
   تجفيفdried over MgSO4
5. 5
   أخرىthe solvent evaporated in vacuo
6. 6
   أخرىIt could, however be recrystallized from ethyl acetate

الإجراء التجريبي

To a suspension of 0.1 mole cysteamine hydrochloride in 20 mL methanol were added 13.6 mL of 25% ammonia solution, followed by dropwise addition of 0.12 mole benzyl bromide at room temperature. The mixture was stirred for 0.5 h, and the formed precipitate of S-dibenzylcysteamine was collected by filtration. The product was extracted with ether (3×100 mL) and the organic phase was successively washed with brine (2×100 mL), dried over MgSO4 and the solvent evaporated in vacuo. The crude product was essentially pure enough for the next step. It could, however be recrystallized from ethyl acetate. Yield 86%, of white solid. m.p. 85–6° C. NMR (CDCl3) in agreement with the title compound.

المصدر