| 摘要 |
The invention comprises compounds of the Formula (I) <FORM:1112627/C2/1> wherein X is methylene or ethylene, each of the radicals R1 is a hydrogen atom, an alkyl group containing up to 5 carbon atoms, an aryl group or halogen atom, R2 is a hydrogen atom, an alkyl group containing up to 20 carbon atoms, an aryl group or halogen atom and each of the radicals R3 is a hydrogen atom or an alkyl group containing up to 5 carbon atoms. Such compounds are prepared by reacting the appropriate cyclic diene and appropriate o-quinone together. 4-PHenyl-4a,5,8,8a-tetra-hydro - 5,8 - methano - 1,2 - naphthoquinone is prepared by oxidizing 4-phenyl catechol in acetone with aqueous iodic acid to obtain 4-phenyl-o-quinone and reacting the latter with cyclopentadiene in petroleum ether solution. 4 - Methyl - 4a,5,8a-tetrahydro-5,8-methano-1,2-naphthoquinone is obtained by treating 4-methyl catechol in ether with silver oxide and sodium sulphate and reacting the product with cyclopentadiene. 4a,5,8,8a - Tetrahydro - 5,8-methano - 1,2 - naphthoquinone is obtained by treating an aqueous ethanol solution containing pyrocatechol and cyclopentadiene with iodic acid. The products are employed as developer precursor in sensitive photographic material.
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