22189
Synthesis and anticancer activity of novel 2 - pyridyl hexahyrocyclooctathieno [ 2 , 3 - d ] pyrimidine derivatives .
 2 - pyridyl hexahyrocyclooctathieno [ 2 , 3 - d ] pyrimidine
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 2 - pyridyl hexahyrocyclooctathieno [ 2 , 3 - d ] pyrimidine