Dimethylamine → Dimethyl 1-(4-Chlorophenyl)-1,4-dihydro-4-oxo-6-methylpyridazine-3-carboxamide

Beteiligte Stoffe

Reaktionsschritte

To an ice cooled suspension of 2.65 g (0.01 mol) 1-(4-chlorophenyl)-1,4-dihydro-4-oxo-6-methyl pyridazine-3-carboxylic Acid (see Example 12) and 1.01 g (0.01 mol) of triethylamine in 50 ml of toluene there is added dropwise 1.09 g (0.01 mol) of ethyl chloroformate. The mixture is stirred at room temperature for 15 min. and is cooled to 5° C. To the mixture there is added 3.375 g (0.03 mol) of 40% dimethylamine (aqueous). The solution formed is stirred at room temperature for 18 hrs. and to it there is added 100 ml of water. The mixture is stirred at room temperature for 1 hr. and the aqueous layer is isolated. The aqueous layer is made basic with 50% sodium hydroxide and extracted with toluene. The toluene extract is dried over magnesium sulfate and concentrated in vacuo to afford 1.8 g of colorless tar. The tar is dissolved in 30 ml of methanol, saturated with anhydrous hydrogen chloride and concentrated in vacuo. The concentrate is slurried in 100 ml of ether for 1 hr. and vacuum filtered. The filter cake is air dried to afford 1.45 g (44% yield) of product, mp 125°-135° C. decomp.

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