18461
The multistep preparation of the new 10 - substituted 2 - ( 1 - piperazinyl ) pyrimido [ 1 , 2 - a ] benzimidazol - 4 ( 10H ) - ones 6a - o , and of the two isomers 10 - ethyl - 2 - ( diethylamino ) pyrimido [ 1 , 2 - a ] benzimidazol - 4 ( 10H ) - one 6p and 10 - ethyl - 4 - ( diethylamino ) pyrimido [ 1 , 2 - a ] benzimidazol - 2 ( 10H ) - one 13 , as well as the in vitro evaluation of their inhibitory activity on human platelet aggregation induced in platelet - rich plasma by ADP , collagen or the Ca ( 2 + ) ionophore A23187 were here described .
 Chemical: 10 - substituted 2 - ( 1 - piperazinyl ) pyrimido [ 1 , 2 - a ] benzimidazol - 4 ( 10H ) - ones; Chemical: 10 - ethyl - 2 - ( diethylamino ) pyrimido [ 1 , 2 - a ] benzimidazol - 4 ( 10H ) - one; Chemical: 10 - ethyl - 4 - ( diethylamino ) pyrimido [ 1 , 2 - a ] benzimidazol - 2 ( 10H ) - one; Chemical: ADP; Chemical: Ca ( 2 + ); Chemical: A23187
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: 10 - substituted 2 - ( 1 - piperazinyl ) pyrimido [ 1 , 2 - a ] benzimidazol - 4 ( 10H ) - ones; Chemical: 10 - ethyl - 2 - ( diethylamino ) pyrimido [ 1 , 2 - a ] benzimidazol - 4 ( 10H ) - one; Chemical: 10 - ethyl - 4 - ( diethylamino ) pyrimido [ 1 , 2 - a ] benzimidazol - 2 ( 10H ) - one; Chemical: ADP; Chemical: Ca ( 2 + ); Chemical: A23187