173531-25-4Relevant articles and documents
Facile sulfur-assisted carbonylation of diaminoresorcinol with carbon monoxide
Mizuno, Takumi,Nakai, Takeo,Mihara, Masatoshi,Ito, Takatoshi
, p. 111 - 116 (2012)
4,6-Diaminoresorcinol, which is a raw material of ZYLON (PBO fiber), has an instability in air atmosphere. Therefore, very stable benzo[1,2-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 benzo[1,2-d:4,5-d']bis-2(3H)-oxazolone and benzo[1,2-d:4,5-d']bis-2(3H)- thiazolone, respectively, in good to excellent yields under similar reaction conditions. Furthermore, 2,6-dimercaptobenzo[1,2-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.
