| Abstract: | 4,6‐Diaminoresorcinol, which is a raw material of ZYLON (PBO fiber), has an instability in air atmosphere. Therefore, very stable benzo1,2‐d:5,4‐d']bis‐2(3H)‐oxazolone recognized a useful equivalent of 4,6‐diaminoresorcinol during the stages of production, storage, and transportation. By combining the sulfur‐assisted carbonylation of 4,6‐diaminoresorcinol dihydrochloride with carbon monoxide and triethylamine under 0.1 MPa at 20°C for 4 h in DMF with the oxidation of resulting hydrogen sulfide salt with molecular oxygen for 2 h, benzo‐1,2‐d:5,4‐d']bis‐2(3H)‐oxazolone was obtained in a quantitative yield. Also, carbonylation of 2,5‐diaminohydroquinone dihydrochloride and 2,5‐diamino‐1,4‐benzenedithiol dihydrochloride was smoothly performed to give benzo1,2‐d:4,5‐d']bis‐2(3H)‐oxazolone and benzo1,2‐d:4,5‐d']bis‐2(3H)‐ thiazolone, respectively, in good to excellent yields under similar reaction conditions. Furthermore, 2,6‐dimercaptobenzo1,2‐d:5,4‐d']bisoxazole, which is another equivalent of 4,6‐diaminoresorcinol, was obtained in excellent yield by the thiocarbonylation of 4,6‐diaminoresorcinol dihydro‐chloride with carbon disulfide in the presence of 1‐methylpyrrolidine at 20°C for 24 h in DMF. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 23:111–116, 2012; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.20746 |
