Isoquinoline → isoquinolin-N-oxide

Participants

Reaction Steps

To a solution of isoquinoline (76.93 g, 595.6 mmol) in acetic acid (520 mL) was added portionwise every 10 min. 33.6 g of sodium perborate, NaBO3.4H2O. Over a 1 hour period a total of 201.6 g (1.31 mole) of perborate was added. The resulting mixture was stirred at 60° C. for 24 hours after which acetic acid was removed by passing a stream of air over the surface of the liquid contained in a large flat vessel overnight. The remaining solid was dissolved in 1 L of water and the solution neutralized with solid sodium bicarbonate. The solution was extracted with chloroform (3×300 mL) and the organic extracts dried over magnesium sulfate. Chloroform was evaporated and the residual white solid was redissolved in chloroform and precipitated by addition of hexane to give 65 g (75%) of the N-oxide: mp 138-140° C. (lit mp 141-142° C.)

Provenance & Evidence