Preparation method of targeted drug AZD3759 intermediate

The invention discloses a preparation method of a targeted drug AZD3759 intermediate, which comprises the following steps of: firstly, 6-nitro veratric acid is hydrolyzed under alkaline conditions toobtain 2-nitro-4-methoxy-5-hydroxybenzoic acid, the 2-nitro-4-methoxy-5-hydroxybenzoic acid is then reduced by hydrazine hydrate under the action of catalyst ferric chloride hexahydrate activated carbon mixture to obtain 2-amino-4-methoxy-5-hydroxybenzoic acid, 2-amino-4-methoxy-5-hydroxybenzoic acid is reacted with formamidine acetate to obtain 4,6-dihydroxy-7-methoxyquinazoline, 4,6-dihydroxy-7-methoxyquinazoline is reacted with acetyl chloride under alkaline conditions to obtain 4-hydroxyl-6-acetoxy-7-methoxyquinazoline, finally 4-hydroxyl-6-acetoxy-7-methoxyquinazoline is reacted with 3-chlorine-2-fluoroaniline by Mitsunobu reaction under the action of triphenylphosphine and azo reagent to obtain 4-[(3-chloro-2-fluorophenyl)amino]-6-acetoxy-7-methoxyquinazoline. The invention reduces the synthesis steps, reduc