28083
Synthesis of an appropriate non - radioactive O - desmethyl precursor was achieved from EMPA with sodium iodide and chlorotrimethylsilane .
 O, EMPA, sodium iodide, chlorotrimethylsilane
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 O, EMPA, sodium iodide, chlorotrimethylsilane