1: With ammonium hydrogen carbonate in methanol; water T=65 - 70°C; 5 h; 2: With sodium hydroxide in methanol; water T=120°C; 4 h; 3: With sulfuric acid in methanol; water pH=7 - 8;
参考文献
Robert C. C. Wu
Patent: US2004/176637 A1, 2004 ;
Location in patent: Page 3 ;