Tributylvinyltin → HCID 59946906, compound

Participants

Reaction Conditions

Reaction Steps

30 g of 3-(3-fluoro-5,6-dichloro-2-pyridyl)-4-chloro-5-difluoromethoxy-1-methyl-[1H]-pyrazole (Example H21) are dissolved in 200 ml of N,N-dimethylformamide (DMF). After addition of 32.9 g of vinyltributyltin, the mixture is twice evacuated and gassed with argon. A little (i.e. a spatula-tip) 2,6-di-tert-butyl-p-cresol and 3.0 g of bistriphenylphosphinepalladium dichloride (PdCl2(PPh3)2) are then added and the mixture is stirred at a temperature of 67° C. for 24 hours. After cooling to 22° C., the reaction mixture is filtered over Hyflo and partitioned between dilute hydrochloric acid and diethyl ether. The ether phase which has been separated off is washed with water, dried over sodium sulfate, filtered and concentrated in vacuo. 84 g of a black oil are obtained, and this is purified over a silica gel flash column (eluting agent: n-hexanelethyl acetate 6/1). The resulting solid is stirred with 100 ml of n-hexane for a further 2 hours, filtered off, washed and dried. 16.4 g of the desired title compound are obtained as a white solid of melting point 75-77° C.

Provenance & Evidence