To obtain a novel derivative that has a specific acetylenic bond, storing against light such as sunlight, has high solubility in solvents, can readily form a recording layer by coating and give an optical recording medium of high recording sensitivity.

This compound is represented by formula I [M is two hydrogen atoms, a divalent metallic atom or a trivalent or tetravalent metal derivative; R1-R4 are each a (substituted) alkyl, an aryl, cycloalkyl], typically tetra(3,3- dimethyl-1-butynyl)phthalocyanine. The objective compound is prepared, for example, by reducing nitrophthalonitrile of formula II, diazotizing, allowing to react with an acetylene compound and heating the resultant compound of formula III together with a metal compound in a solvent such as quinoline at 150-250°C for 1-5 hours.