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 and biological activities of some novel aminomethyl derivatives of 4-substituted-5-(2-thienyl)-2,4-dihydro-3H-1,2,4-triazole-3-thiones. A novel series of compounds were synthesized by cyclic condensation reaction of substituted isothiocyanate (2a-c) with 2-thiophenecarboxylic acid hydrazide (1) in the presence of ethyl alcohol, to obtain intermediate thiosemicarbazides (3a-c), which were further treated with sodium hydroxide in the presence of ethanol to obtain triazole derivatives (4a-c). The latter were refluxed with substituted secondary amines and formaldehyde for 6-10 h to afford Mannich bases (5a-k). The synthesized compounds were characterized on the basis of their spectral (IR, (13)C and (1)H NMR) data and evaluated for biological activities. Some of the compounds were found to exhibit significant antimicrobial and antioxidant activity.
{"Chemical": ["aminomethyl", "isothiocyanate", "2-thiophenecarboxylic acid hydrazide", "sodium hydroxide", "(13)C", "formaldehyde", "4-substituted-5-(2-thienyl)-2,4-dihydro-3H-1,2,4-triazole-3-thiones", "ethanol", "triazole", "ethyl alcohol", "thiosemicarbazides", "secondary amines", "Mannich bases", "(1)H"]}