1-Butanol → 3'-isopropyl-3,4-dihydro-2H-1,5-benzodioxepin-3-spiro-5'-oxazolidin-2'-one

Participants

Reaction Steps

A mixture of 3-hydroxy-3-isopropylaminomethyl-3,4-dihydro-2H-1,5-benzodioxepin (11.85 g.; 50 millimoles), prepared as described in Example 1, and dibutyl carbonate (13.1 g.) with a small piece of metallic sodium is heated in an oil bath. The temperature then is slowly raised to 170° C. with removal of butanol. Finally, the mixture is heated between 170°-200° C. with removal of excess dibutyl carbonate. The cooled reaction product is dissolved in benzene, washed with water, dried over sodium sulfate, and the solvent evaporated to give 3'-isopropyl-3,4-dihydro-2H-1,5-benzodioxepin-3-spiro-5'-oxazolidin-2'-one, m.p. 121°-122° C.

Provenance & Evidence