| 摘要 |
Pyridoxal - 51 - orthophosphate is prepared by phosphorylating N-(2-methyl-3-hydroxy-5-hydroxymethyl - 4 - pyridyl - methylidene)-hydrazine by heating with a mixture of polyphosphoric acids (prepared by heating orthophosphoric acid with phosphorus pentoxide), hydrolysing the resultant polyphosphate to the orthophosphate and then subjecting this to diazodegradation, i.e. replacing the hydrazono radical by an oxygen atom. The hydrolysis may be carried out by heating the polyphosphate, with dilute acid, and the diazodegradation by heating with nitrous acid; the hydrolysis and diazodegradation may be carried out simultaneously. An example is given. |
