公开(公告)号：US2703323A

公开(公告)日：1955-03-01

申请号：US29625852

申请日：1952-06-28

Applicant: HOFFMANN LA ROCHE

Inventor： PAUL KARRER ,  MAX VISCONTINI

IPC: C07D213/66 ,  C07F9/58

CPC classification number: C07D213/66 ,  C07F9/582

公开(公告)号：US2740775A

公开(公告)日：1956-04-03

申请号：US32034452

申请日：1952-11-13

Applicant: HOFFMANN LA ROCHE

Inventor： PAUL KARRER ,  MAX VISCONTINI

IPC: C07F9/09 ,  C07F9/6561

CPC classification number: C07F9/65618 ,  C07F9/091

公开(公告)号：US2792402A

公开(公告)日：1957-05-14

申请号：US30789752

申请日：1952-09-04

Applicant: HOFFMANN LA ROCHE

Inventor： PAUL KARRER ,  MAX VISCONTINI

IPC: C07F9/58

CPC classification number: C07F9/582

Abstract: A process for the manufacture of pyridoxamin derivatives comprises reacting pyridoxamin or a salt thereof with metaphosphoric acid, hydrolysing the product and, if desired, converting the pyridoxamin-51-monophosphoric acid ester so formed into its magnesium or alkaline earth metal salts. The metaphosphoric acid is produced by slowly heating orthophosphoric acid until water ceases to distil off and the liquid becomes turbid. The initial reaction product contains pyridoxamin-51-triphosphoric acid, probably together with higher and lower phosphoric acid esters. Hydrolysis may be effected by heating the initial product with water or acid. Examples describe the preparation of the monophosphate by the above method. It is converted to its magnesium salt by reaction with magnesium hydroxide at pH 6 to 7 and filtered off; a further quantity of the salt is recovered by treating the mother liquor at pH 8-9 with more magnesium hydroxide. The calcium salt is obtained by reacting the magnesium salt with calcium acetate or by reacting the monophosphate with calcium hydroxide.