1,2-Dimethoxyethane → 3-Vinyl-6,7-dihydro-[1,4]dioxino[2,3-c]pyridazine

Participants

Reaction Conditions

Reaction Steps

A solution of 3-chloro-6,7-dihydro[1,4]dioxino[2,3-c]pyridazine (13.6 g, 0.079 mol) containing ca. 15% of a bromo species in dimethoxyethane (400 ml) was degassed under argon for 10 min then tetrakis(triphenylphosphine)palladium (0) (2 g), potassium carbonate (10.33 g), triethenylboroxin pyridine complex (11.32 g) and water (55 ml) were added. The mixture was heated at 95° C. for 48 h and cooled and evaporated to dryness. The mixture was treated with aqueous sodium bicarbonate solution and extracted (5×) with DCM. Extracts were dried (sodium sulphate), evaporated and the residue chromatographed on silica gel (500 g), eluting with 0-100% ethyl acetate-hexane, affording the product (6.43 g, 50%); [also some impure fractions (1.8 g)]

Provenance & Evidence