Welcome to chemicalbook!
Chinese English Japanese Germany Korea
400-158-6606
Try our best to find the right business for you.
Do not miss inquiry messages Please log in to view all inquiry messages.

Welcome back!

ChemicalBook CAS DataBase List Pyrimethanil

Pyrimethanil synthesis

8synthesis methods
Pyrimethanil is produced by reaction of 2-bromo-4,6-dimethylpyrimidine with aniline.
-

Yield:53112-28-0 81.3%

Reaction Conditions:

Stage #1: CYANAMID;anilinewith hydrogenchloride in water at 45 - 90; pH=2.5; for 2 h;Inert atmosphere;
Stage #2: acetylacetonewith sodium hydroxide in water; pH=7.9; for 1 h;

Steps:



A nitrogen-inertized flange reactor was initially charged with aniline and 50% cyanamide solution in water. Subsequently, 32% hydrochloric acid was metered in up to a pH of 2.5. After the metered addition of HCl, the mixture was heated from internal temperature 45° C. to 95° C. within two hours. During the heating phase the pH was kept at 2.5 by adding further hydrochloric acid. Subsequently, acetylacetone was pumped in at internal temperature 80° C., and 50% sodium hydroxide solution was metered in up to a pH of 7.9. After a continued stirring period of one hour, the lower aqueous phase was removed. The acetylacetone excess of the upper phase was distilled off at a pressure of 750-35 mbar up to a maximum bottom temperature of 125° C. The acetylacetone distilled off can be used in subsequent batches.The bottoms were cooled to 80° C. and admixed with isopropanol. This was followed by cooling gradually to internal temperature of 0° C., and filtration of the product slurry with suction through a glass filter crucible. The reactor was rinsed through with water, which was filtered with suction. The product was washed twice with isopropanol and dried in a vacuum drying cabinet at 70° C. and 10 mbar.The isolated yield was 324 g=1.626 mol=81.3% of theory at a product purity of 97.6% (HPLC with internal standard*)) or 99.9% (GC area %**)). **) GC: 30 m DB 1701* 0.32 mm, film thickness 0.25 μm, injector 250° C., detector (FID) 300° C., injection volume 0.2 μl (0.1 g/liter of methanol), program: 50° C. (2 min), 10° C./min to 250° C. (8 min).*) HPLC: 1100 series from Agilent; Nucleosil column 120-5 C18 250×4 mm; instrument parameters: injection volume 5 μl, flow rate 1 ml/min, temperature RT, column pressure 90 bar, detector wavelength 268 nm, chromatography time 8 min; mobile phase: 250 ml of Millipore water, 750 ml of acetonitrile, 1 g of ammonium acetate; sample preparation phase: 250 ml of Millipore water, 750 ml of acetonitrile; pyrimethanil standard with known content.

References:

US2011/137033,2011,A1 Location in patent:Page/Page column 2

Pyrimethanil Related Search: