The invention relates to the field of
medicinal chemistry, and particularly discloses a novel TLR8
agonist intermediate as well as a preparation method and application thereof, which are suitable for
process development of 4, 6-diaminopyridino [3, 2-d]
pyrimidine TLR8 agonists. According to the preparation method, tert-butyl is adopted to replace 2, 4-dimethoxybenzyl to serve as an amino
protecting group, so that the
crystallization property of the intermediate is remarkably improved,
column chromatography is avoided, the cost is reduced, and the process stability is improved. The preparation method of the TLR8
agonist intermediate comprises the steps of reduction, acylating chlorination,
coupling,
amination and the like, has the advantages of being easy and convenient to operate, high in yield,
environmentally friendly and the like, and is particularly suitable for industrial production.