Sulfuric acid magnesium salt (1:1) → HCID 67404927, compound

Participants

Reaction Steps

To a suspension of MgSO4 (18.4 g, 0.154 mol) in DCM (500 ml) were added 1,4-dioxaspiro[4.5]decan-8-one (48.0 g, 0.308 mol) and 4-fluorophenylhydrazine hydrochloride (50.0 g, 0.308 mol). Then, TEA (43.8 ml, 0.308 mol) was added dropwise over 5 min. The internal temperature went up from 17° C. to 25° C. upon addition of TEA. The resulting suspension was allowed to stir at rt for 4 h and filtered. The white solid was washed twice with DCM and the filtrate was concentrated in reduced pressure. The orange slurry was suspended in toluene (500 ml) and ZnCl2 (38.6 g, 0.283 mol) was added. The resulting dark orange solution was stirred at reflux using a Dean-Stark apparatus for 12 h. After cooling to rt, the resulting black mixture was filtered over celite. The solid was washed with isopropyl acetate, the organic filtrate was basified with 1N NaOH (until pH ˜12). The aqueous phase was extracted with isopropyl acetate, the combined organic extracts were passed through celite, dried over Na2SO4, filtered and concentrated in vacuo to yield the titled compound as a dark brown solid.

Provenance & Evidence