Dichloromethane → 1,3-Benzodioxole

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To 28 mg PdCl2(dppf).CH2Cl2 in a reaction tube under nitrogen were added 4 ml dioxane, 0.43 ml (3 mmol) triethylamine, 0.23 ml (1.5 mmol) pinacolborane and 262 mg (1.06 mmol) 1-iodo-3,4-methylenedioxybenzene. The reaction solution was warmed to 80° C. with stirring in an oil bath for 22 h. An aliquot (0.3 ml) was removed from the reaction and extracted into ethyl acetate and washed several times with water and analysed by gc (fid detector, SGE HT5 capillary column). All the 1-iodo-3,4-methylenedioxybenzene had reacted to form the boronic acid ester together with some 1,3-benzodioxole. After addition of 8 ml methanol (which destroys the excess pinacolborane and thereby prevents the formation of symmetrical biaryl), 1.07 g Cs2CO3 and 261 mg (1.06 mmol) 4-iodobenzamide, the solution was warmed to 40° C. for 17 h. An aliquot (0.5 ml) was removed from the reaction solution and extracted into ethyl acetate and washed several times with water, and analysed by gc (fid detector, SGE HT5 capillary column). The required biaryl (identified by gc/ms) gave rise to the strongest peak in the gc trace.

Herkunft & Nachweise