Formaldehyde → HCID 18693270, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of butyl 6-ethylaminopyridazine 3-carboxylate (described in reference example 13)(10.0 g, 44.8 mmol) and para-formaldehyde (1.7 g, 56.6 mmol) in TFA (100 ml was stirred at 50-60° C. for 1 hour until a clear solution formed. The solution was cooled to ambient temperature and treated with 4-fluorophenol (5.6 g, 50 0 mmol), stirred for 16 hours and evaporated at reduced pressure. The residue was partitioned between ice/water (200 g) and dichloromethane (200 ml), the organic layer washed with saturated sodium bicarbonate solution, dried over anhydrous magnesium sulphate and evaporated to give a yellow gum. Chromatography on silica, eluting with 10% ether in dichloromethane, gave a solid which crystallised from ether to give butyl 6-[N-(5-fluoro-2-hydroxybenzyl)-N-ethylamino]pyridazine-3-carboxylate as pale pink needles (2.2 g).

Provenance & Evidence