Pyridine → HCID 57274384, compound

Participants

Reaction Steps

(3S,4S)-3,4-Dihydro-6-(3,4-dimethoxyphenyl)sulphonyl-3,4-epoxy-2,2,3-trimethyl-2H-benzo[b]pyran (3.0 g) (see Preparation 25) and 2,3-dihydro-2-methyl-3-oxo-6-hydroxypyridazine (2.0 g) (see J.Org.Chem, 1971, 36, 3372) were suspended in dry 1,4-dioxane (30 ml), pyridine (0.61 g) was added and the mixture heated under reflux (a calcium chloride drying tube was attached to the flask) for 2 days. The solvent was removed under reduced pressure, the residue stirred with 5% methanol/dichloromethane and filtered. The filtrate was evaporated and the crude product chromatographed on silica eluting with 2.5:97.5 methanol: dichloromethane as the eluent to yield (3S,4R)-3,4-dihydro-4-(2,3-dihydro-2-methyl-3-oxo-pyridazin-6-yl)oxy-6-(3,4-dimethoxyphenyl)sulphonyl-3-hydroxy-2,2,3-trimethyl-2H-benzo[b]pyran (1.7 g) as a yellow foam.

Provenance & Evidence