Potassium Hydroxide → (6-Hydrazinopyridin-3-yl)methanol

Temperatur

150 °C

220.0 g (1.5 mol) (6-chloropyridin-3-yl)methanol [Evans et al., Organic Letters 2001, 19, 3009-3012] are initially introduced into 746 ml (767.1 g, 15.3 mol) hydrazine hydrate and the mixture is stirred at a bath temperature of 150° C. for 5 h. The reaction mixture is concentrated in vacuo, the residue is taken up in 500 ml water and 86.0 g (1.5 mol) potassium hydroxide are added. The mixture is stirred for 15 min, the water is then removed almost completely on a rotary evaporator and the residues of water are distilled off azeotropically with toluene several times. The oily residue is stirred in ethanol, the mixture is cooled to approx. 10° C., the potassium chloride which has precipitated out is filtered off, the filtrate is concentrated, diethyl ether is added to the residue and the mixture is stirred. Finally, the product is filtered off, the residue on the filter is washed with diethyl ether and the crystals are dried in vacuo.

1. concentrationThe reaction mixture is concentrated in vacuo
2. stirringThe mixture is stirred for 15 min
3. customthe water is then removed almost completely on a rotary evaporator
4. distillationthe residues of water are distilled off azeotropically with toluene several times
5. stirringThe oily residue is stirred in ethanol
6. temperaturethe mixture is cooled to approx. 10° C.
7. customthe potassium chloride which has precipitated out
8. filtrationis filtered off
9. concentrationthe filtrate is concentrated
10. additiondiethyl ether is added to the residue
11. stirringthe mixture is stirred
12. filtrationFinally, the product is filtered off
13. washthe residue on the filter is washed with diethyl ether
14. customthe crystals are dried in vacuo

ORD-Eintrag

ord-cbeb5514a87a487babea13ccc4783fa1

Quelldatensatz

uspto-grants-2014_02

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08653111B2