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), 2,4,6-trivinylcyclotriboroxane pyridine complex (11.32 g) and water (55 ml) were added. The mixture was heated at 95° C. for 48 hours 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