Sodium Hydroxide → HCID 23317187, compound

Participants

Reaction Conditions

Reaction Steps

A solution of 18.6 g of phosphorus oxybromide in 18.6 g of absolute toluene was diluted with 100 ml of absolute toluene in a sulphonation flask under nitrogen, heated to 65° C. and treated dropwise within 1.5 hours with a solution of 21.6 g of 6-pentyl-3(2H)-pyridazinone (prepared according to Example 3) in 100 ml of absolute toluene. A grey coloured difficultly stirrable suspension formed occasionally. For the completion of the reaction, the mixture was stirred at 65° C. overnight (18 hours), then cooled to room temperature, poured into 250 ml of water and stirred well. The aqueous phase was neutralized with 28% (wt./vol.) sodium hydroxide solution and with sodium hydrogen carbonate. The organic phase was separated and the aqueous phase was back-extracted with 100 ml of tert.butyl methyl ether. The combined organic phases were washed with 100 ml of water, dried over sodium sulphate and evaporated on a rotary evaporator. The brown coloured crude product was subsequently distilled in a high vacuum, there being obtained 21.4 g (72%) of 3-bromo-6-pentylpyridazine in the form of a brown oil (b.p. 99°-108° C./0.04-0.06 Torr) which crystallized upon cooling. Recrystallization of a sample from methyl formate at -20° C. gave white crystals of melting point 31°-32° C.

Provenance & Evidence