19922
A variety of 2 - alkoxy - 4 - aryl - 6 - ( 1H - benzimidazol - 2 - yl ) - 3 - pyridinecarbonitriles 4a - r were prepared via either regioselective reaction of 3 - aryl - 1 - ( 1H - benzimidazol - 2 - yl ) - 2 - propen - 1 - ones 3 with malononitrile or ylidenemalononitriles 6 with 2 - acetyl - 1H - benzimidazoles 1 in the presence of sodium alkoxide in the corresponding alcohol .
 Chemical: 2 - alkoxy - 4 - aryl - 6 - ( 1H - benzimidazol - 2 - yl ) - 3 - pyridinecarbonitriles; Chemical: 3 - aryl - 1 - ( 1H - benzimidazol - 2 - yl ) - 2 - propen - 1 - ones; Chemical: malononitrile; Chemical: ylidenemalononitriles; Chemical: 2 - acetyl - 1H - benzimidazoles; Chemical: sodium alkoxide; Chemical: alcohol
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: 2 - alkoxy - 4 - aryl - 6 - ( 1H - benzimidazol - 2 - yl ) - 3 - pyridinecarbonitriles; Chemical: 3 - aryl - 1 - ( 1H - benzimidazol - 2 - yl ) - 2 - propen - 1 - ones; Chemical: malononitrile; Chemical: ylidenemalononitriles; Chemical: 2 - acetyl - 1H - benzimidazoles; Chemical: sodium alkoxide; Chemical: alcohol