You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Chemical"].

Please return the output as a JSON object of the format: {"Chemical": ["Arsenic", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Synthesis of substituted 6-amino-4-(2,4-dimethoxyphenyl)-[1,2]dithiolo[4,3-b]pyrrol-5-ones and their raising leukocyte count activities. The design and synthesis of a series of substituted 6-amino-4-(2,4-dimethoxyphenyl)-[1,2]dithiolo[4,3-b]pyrrol-5-ones are described. All the synthesized compounds were evaluated for raising leukocyte count activities in normal mice. Four compounds (8a, b, d, h) exhibited raising leukocyte count activities close or higher than positive control recombinant human granulocyte colony stimulating factor (rhG-CSF), and some (8e-g, k, p, r) had a moderate effect. Among them, the most potent compound 8a was evaluated for its antileukopenia activity in cyclophosphamide (CTX) treated mice. Interestingly, 8a exhibited significant antileukopenia activity as compared to rhG-CSF. The results suggest that this kind of compounds might be utilized for the development of new candidate for treatment of leukocytopenia.
{"Chemical": ["6-amino-4-(2,4-dimethoxyphenyl)-[1,2]dithiolo[4,3-b]pyrrol-5-ones", "cyclophosphamide"]}