Phosgene → HCID 12848791, compound

Participants

Reaction Conditions

Reaction Steps

4.3 g (49.9 millimoles) of 1-cyclopropylethanol are added dropwise to a stirred solution of 9.9 g (100 millimoles) of phosgene in 100 ml of absolute ether at 0° C. The reaction solution is then stirred for 1 hour at 0° C. followed by one hour at room temperature, and the excess phosgene is removed by means of a dry stream of nitrogen, after which the ether is removed under reduced pressure at room temperature. The 1-cyclopropylethyl chloroformate which is left (6.6 g) is reacted with 5.0 g (24.6 millimoles) of 6-(p-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone by the method described in Example 31. The reaction mixture is also worked up as described in Example 31. After recrystallizing the product first from dimethylformamide/water and then from ethanol/ether, 1.3 g (17% of theory) of 6-[p-(1-cyclopropylethoxycarbonylamino)-phenyl]-4,5-dihydro-5-methyl-3(2H)-pyridazinone are obtained as colorless crystals of melting point 223°-224° C.

Provenance & Evidence