| 摘要 |
NEW MATERIAL:A compound of formula I (R<1>-R<4> are 1-4C alkyl). EXAMPLE:2,7-bis(dimethylamino)-anthrone of formula II. USE:Color developing agent for heat-sensitive recording materials. Capable of obtaining color-developed printed images with near-infrared absorption. When contacted with an electron-accepting matter, giving dense, clear color tone of green-black-base. PREPARATION:First, a p-aminobenzadebyde derivative of formula III and a m-aminobenzoic acid derivative of formula IV are refluxed on heating in acetic anhydride/glacial acetic acid to effect dehydrocondensation, thus synthesizing a 3-(p-aminophenyl)-6-aminophthalide derivative of formula V. Thence, this compound is reduced, using zinc powder, in acetic acid at 90 deg.C to produce a 2-(p-aminobenzyl)-5-aminobenzoic acid derivative of formula VI. Finally, this compound is put to dehydrocondensation at 100 deg.C in polyphosphoric acid or a phosphoric ester. |
