Ammonia → 2-Amino-4,6-difluoropyrimidine

Temperatur

25 °C

69.7 g (4.1 mol) of liquid ammonia were added at -30° to -20° C. to a stirred mixture of 250 g (1.865 mol) of 2,4,6-trifluoropyrimidine and 3.3 1 of diethyl ether within 1 hour. To work up, the reaction mixture was warmed to 25° C. and the precipitate was filtered off. Washing with ether, stirring in water, renewed filtration and drying resulted in 203 g (83% of theory) of the desired product (melting point 214°-216° C.). It was possible by concentrating the ether filtrate to about 1/3 of its volume to isolate a further 20 g (8% of theory) of this compound, of melting point 193°-196° C., from a 1:1 mixture with the isomeric 4-amino compound. Comparative experiment (according to SU-A 547,447--1975)

1. filtrationthe precipitate was filtered off
2. washWashing with ether
3. filtrationfiltration
4. customdrying

ORD-Eintrag

ord-724dbf67b047439b9a8f67d2e9ce2ad2

Quelldatensatz

uspto-grants-1991_04

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05011927