HCID 15557329, compound → HCID 15557332, compound

Participants

Reaction Steps

A mixture of 7-hydroxy-3'-isopropyl-3,4-dihydro-2H-1,5-benzodioxepin-3-spiro-5'-oxazolidin-2'-one (200 mg.; 0.716 mmole), barium hydroxide octahydrate (1.08 g.; 3.42 mole) and water (3.2 ml.) in an evacuated sealed glass tube (a Carius tube) is heated in a rocking oven at 160°-165° C. for 16 hours. The reaction mixture then is poured into boiling water (60 ml.) with stirring and vigorous passage of carbon dioxide until all barium ions have been removed from solution (pH ca. 6.8 by narrow range paper: no precipitate when a small portion is tested with sulfate ions). The solution is filtered through a little celite and evaporated to dryness under reduced pressure, affording 187 mg. of pale brown scaly solid. The crude product is purified by dry column chromatography on silica gel deactivated with 15% of water, using 3% methanol in ether for the development. The desired product is the second component to be eluted from the column, 70.5 mg., (38.9%). After drying at 60° C. in air, the solid still contains water of crystallization and has m.p. ca. 108°-110° C. The anhydrous compound is obtained by drying the hydrate at 80° C./0.1 m.m. for 1 hour and then has m.p. 133°-134.5° C. Recrystallization from benzene (ca. 30 parts V/W) provides 3,7-dihydroxy-3-isopropylaminomethyl-3,4-dihydro-2H-1,5-benzodioxepin, m.p. 133.5°-135° C.

Provenance & Evidence