Synthesis method for 6-amino-2,2-dimethyl-2H-pyridino-[3,2-b] [1,4] oxazine-3(4H)-ketone

Abstract

The invention relates to the field of chemical synthesis, in particular to a synthesis method for 6-amino-2,2-dimethyl-2H-pyridino-[3,2-b] [1,4] oxazine-3(4H)-ketone, which is characterized by including the steps of carrying out percyclic reaction of 2-amino-3-hydroxypyridine serving as a raw material and 2-bromine-2-methyl propionic acid ethyl in the presence of potassium carbonate, then dropwise adding mixed acid of concentrated sulfuric acid and fuming nitric acid into a reaction system, selectively obtaining 2,2-dimethyl-6-nitryl-2H-pyridino-[3,2-b] [1,4] oxazine-3(4H)-ketone by means of nitration, and finally obtaining a target compound after reduction. The synthesis method has the advantages of high yield, mild reaction conditions and the like, and has large-scale preparation value.

Description

Technical field:

[0001] The invention relates to the field of chemical synthesis, in particular to a synthesis method of 6-amino-2,2-dimethyl-2H-pyridin[3,2-b][1,4]oxazin-3(4H)-one. Background technique

[0002] 6-Amino-2,2-dimethyl-2H-pyridin[3,2-b][1,4]oxazin-3(4H)-one is a useful drug intermediate, and JP2008013527 reports that it contains such The compound of the core structure is spleen tyrosine kinase (Spleen tyrosine kinase, Syk), which plays an important role in the maturation of lymphocytes and the activation of immune cells. Syk may become a target for the treatment of lymphoma, leukemia and other tumors related to the immune system.

[0003] For the preparation of 6-amino-2,2-dimethyl-2H-pyridin[3,2-b][1,4]oxazin-3(4H)-one, the methods of related compounds reported in literature are as follows:

[0004] Method JP2008 / 013527A reports two preparation methods, which are as follows:

[0005] method one:

[0006]

[0007] Reagents and yield: (I) sodium methoxide...

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