Hydrazine hydrate (1:1) → Hydralazine

Temperatur

50 °C

Again according to the disclosure in the '397 application, to a 2-L, 3-necked, round-bottomed flask fitted with a temperature probe and condenser were charged 700 mL of ethanol and 7.6 mole equivalents (630 mL) of hydrazine hydrate, and the solution was cooled to 50° C. (the '397 application discloses a temperature <10° C.). One (1) mole equivalent (280 g) of 1-chlorophthalazine (solid) was added in portions at a rate to maintain the solution temperature at <20° C. The solution was stirred and heated to 60-70° C. After one hour at that elevated temperature, the hot solution was filtered to remove any insoluble by-products (insoluble matter recovered was 12 g), and the filtrate was cooled to 0 to 5° C. A light yellow solid formed in the cold solution, which was isolated by filtration, washed with cold ethanol, and then dried to constant mass and characterized. The yield was 80% (the yield reported in the '397 application was 77-80%).

1. temperatureto maintain the solution temperature at <20° C
2. temperatureheated to 60-70° C
3. filtrationthe hot solution was filtered
4. customto remove
5. customany insoluble by-products (insoluble matter recovered was 12 g)
6. temperaturethe filtrate was cooled to 0 to 5° C
7. customA light yellow solid formed in the cold solution
8. customwhich was isolated by filtration
9. washwashed with cold ethanol
10. customdried to constant mass

ORD-Eintrag

ord-bb6d8be684774c60a3910db54716eeaf

Quelldatensatz

uspto-grants-2010_10

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07807830B2