[Studies on the synthesis of antiulcer agents. V. Synthesis and antiulcer activity of dihydrobenzofuranone derivatives].

In the preceding paper, we reported that 1-[3-[3-oxospiro[benzofuran-2(3H),1'-cyclopropan]-5- yl]acryloyl]piperidine(1a) and 4-[3-[3-oxospiro[benzofuran-2(3H),1'-cyclopropan]-5- yl]acryloyl]morpholine(1b) have potent antiulcer activities. In this paper, propionic acid derivatives (2,3) and oxyacetic acid derivatives (4, 5, 10) were prepared by converting the acryloyl moiety into propionyl and oxyacetyl groups, and tested for antiulcer activities. As a result, [3-oxospiro[benzofuran-2(3H),1'-cyclopropan]5-yloxy]-a cetamide(4j) exhibited significant antiulcer activities.