Реакция #738596

Уравнение реакции

p-toluenesulfonic acid hydrate

5-chloro-6-ethyl-4-(1,3-dihydroxy-2-propylamino)-pyridine

2-amino-1,3-propanediol

3,4-dichloro-2-ethyl-pyridine

benzaldehyde

→

3-Chloro-2-ethyl-4-(2-phenyl-1,3-dioxan-5-ylamino)-pyridine

Растворители

water

water

toluene

Условия реакции

Обработка

1. 1
   ДругоеWorking up and purification
2. 2
   Другоеthe chromatography over silica gel (ethyl acetate) gave initially 0.6 g of trans isomer (18.8% of theory), melting point: 139-140° C.

Методика

2.3 g (10 mmol) of 5-chloro-6-ethyl-4-(1,3-dihydroxy-2-propylamino)-pyridine (prepared analogously to Example A from 2-amino-1,3-propanediol and 3,4-dichloro-2-ethyl-pyridine) and 5.0 g of benzaldehyde were heated with 2.1 g of p-toluenesulfonic acid hydrate in 40 ml of toluene, using a water separator, until the evolution of water had ended. Working up and purification were carried out analogously to Example A. the chromatography over silica gel (ethyl acetate) gave initially 0.6 g of trans isomer (18.8% of theory), melting point: 139-140° C., and then 2.4 g of cis isomer (75.2% of theory), melting point 119-120° C.

Источник