Synthesis and solubility measurement in supercritical carbon dioxide of two solid derivatives of 2-methylnaphthalene-1,4-dione (menadione): 2-(Benzylamino)-3-methylnaphthalene-1,4-dione and 3-(phenethylamino)-2-methylnaphthalene-1,4-dione

•Two menadione derivatives were synthesized, purified and characterized.•Solubility of menadione derivatives in SC-CO2 was measured at T<333K, p<28MPa.•Thermodynamic consistency of solubility data measured was evaluated.•Solubility data was correlated in terms of temperature and CO2 density.