28083
Synthesis of an appropriate non - radioactive O - desmethyl precursor was achieved from EMPA with sodium iodide and chlorotrimethylsilane .
 Chemical: O; Chemical: EMPA; Chemical: sodium iodide; Chemical: chlorotrimethylsilane
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: O, EMPA, sodium iodide, chlorotrimethylsilane 
Answer:
 Chemical: O; Chemical: EMPA; Chemical: sodium iodide; Chemical: chlorotrimethylsilane