in neat (no solvent) in vacuo or under inert gas, heated at 240°C for 5 h;
参考文献
Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), , vol. 30, p. 1542 - 1547
Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, , vol. 30, p. 1874 - 1879
