1-(3,4-Dimethylphenyl)-3-methyl-4-nitroso-1H-pyrazol-5-ol is an intermediate used in the synthesis of N-Hydroxy Eltrombopag (H825795), which is a derivative compound of Eltrombopag (508000), an agonist of the Thrombopoietin (Tpo) receptor, used as treatment for thrombocytopenia.