19836
Significant improvement in antiviral potency was achieved when substituents were introduced at positions N1 , C4 , C7 and C8 on the benzofuranopyrimidone scaffold .
 Chemical: benzofuranopyrimidone
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: benzofuranopyrimidone