20192
Focused library synthesis and structure - activity relationship development of 5 , 6 , 7 - substituted pyrazolopyrimidines led to the discovery of 2 - ( 5 , 7 - diethyl - 2 - ( 4 - ( 2 - fluoroethoxy ) phenyl ) pyrazolo [ 1 , 5 - a ] pyrimidin - 3 - yl ) - N , N - diethylacetamide ( 6b ) , a novel translocator protein ( TSPO ) ligand exhibiting a 36 - fold enhancement in affinity compared to another pyrazolopyrimidine - based TSPO ligand , 6a ( DPA - 714 ) .
 Chemical: 5 , 6 , 7 - substituted pyrazolopyrimidines; Chemical: 2 - ( 5 , 7 - diethyl - 2 - ( 4 - ( 2 - fluoroethoxy ) phenyl ) pyrazolo [ 1 , 5 - a ] pyrimidin - 3 - yl ) - N , N - diethylacetamide; Chemical: pyrazolopyrimidine; Chemical: DPA - 714
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: 5 , 6 , 7 - substituted pyrazolopyrimidines; Chemical: 2 - ( 5 , 7 - diethyl - 2 - ( 4 - ( 2 - fluoroethoxy ) phenyl ) pyrazolo [ 1 , 5 - a ] pyrimidin - 3 - yl ) - N , N - diethylacetamide; Chemical: pyrazolopyrimidine; Chemical: DPA - 714