Synthesis of the tetrapyrrolic macrocycle 3,4,8,9,17,18,22,23-octamethyl-30,31,33,34-tetraazaheptacyclo [23.3.1.1², ⁵.1⁷, ¹⁰-1¹¹, ¹⁵.1¹⁶, ¹⁹.1²¹, ²⁴] tetratriaconta-1,3,5,7(33),8,10,15(32),16,18,20,22,24(30),25(29)-tridecaene