29581
Buchwald - Hartwig coupling reaction of substituted anilines with pivaloyl protected 2 , 4 - diamino - 6 - bromo - pyrido [ 2 , 3 - d ] pyrimidine was successfully explored to synthesize these analogs .
 Chemical: pivaloyl; Chemical: 2 , 4 - diamino - 6 - bromo - pyrido [ 2 , 3 - d ] pyrimidine
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: pivaloyl; Chemical: 2 , 4 - diamino - 6 - bromo - pyrido [ 2 , 3 - d ] pyrimidine