Sodium Hydroxide → Isoxepac

Participants

Reaction Steps

To 49 ml of absolute ethanol is added with vigorous stirring, 81 g of phosphorus pentoxide. After addition, the mixture is allowed to stir at 95°-100° C for 1 hour, 400 ml of tetramethylene sufone are added and the temperature is adjusted to 86°-90° C. Then, 38.5 g of 4-(2-carboxybenzyloxy)phenylacetic acid, Example 1, are added, the mixture is stirred for 4 hours and poured onto ice water. The aqueous mixture is made basic with sodium hydroxide and extracted with toluene. Cooling of the aqueous layer followed by acidification with concentrated hydrochloric acid gives light brown crystals. Recrystallization from acetic acid-water or from dimethoxyethane provides colorless crystals, mp 126°-128° C of 6,11-dihydro-11-oxodibenz[b,e]oxepin-2-acetic acid.

Provenance & Evidence