PURPOSE: To produce a pentamethinecyanine compd. and an intermediate thereof simply and easily at a low cost by reacting specific compds.

CONSTITUTION: A compd. of formula 1 and/or a compd. of formula II is reacted with a compd. of formula III to give a compd. of formula IV. In formulas 1 to IV, Z1 and Z2 are each an atomic group necessary to form a 6- or 7-membered nitrogenous heterocyclic ring; Q1 is an atomic group necessary to form a 5-, 6-, or 7-membered ring; R1, R2, and R3 are each alkyl; L1, L2, L3, L4, L5, L6, and L7 are each a methine group; L1' and L2' are each an active methyl group; n1 and n2 are each 0 or 1; M1, M2, and M3 are each a charge-neutralizing counter ion; and m1, m2, and m3 are each a number necessary to neutralize the charge on the molecule and 0 or higher. By reacting the compd. of formula 1 with the compd. of formula III, a compd. of formula V and/or a compd. of formula VI, which is an intermediate of the compd. of formula IV, is prepd. In formulas V and VI, Z1, Q1, R1, R3, L1, L2, L4, L5, and n1 are each as defined above; M4 and M5 are each the same as M1 described above; and m4 and m5 are each the same as m1 described above.