In addition, the abbreviations described in the tables have the meanings as defined below: TABLE 1 Melting Point No. R1 R2 R3 R4 R5 (X)n Z (° C.) 1-1 Et H Me Me Me 3-Br-6-Cl O 80-81 1-2 Et H Me Me Me 3-CF3 O viscous oil 1-3 Et H Me Me Me 3-Br-5-Cl O ...