Synthesis of Some Pyrimidine, Pyrazole, and Pyridine Derivatives and Their Reactivity Descriptors

Table 1

The structure-properties relationships in gas phase reflecting the effect of molecular structure on the associated energy and thermodynamic parameters, which are important for molecular characterization (HOMO-LUMO values of geometry-optimized molecules in acetonitrile (ACN) are also given).

Molecule label	Energy (kcal/mol)	Gas		ACN acetonitrile		Dipole (debye)	H° (kcal/mol)	G° (kcal/mol)	S° (J/mol·K)
		EHOMO (eV)	ELUMO (eV)	EHOMO (eV)	ELUMO (eV)
1	−739848	−8.36	−1.15	−8.11	−1.15	5.97	−739716	−739755	130.73
2	−832472	−8.52	−0.94	−8.31	−0.99	6.35	−832327	−832368	136.44
3	−1035131	−8.52	−1.01	−8.33	−1.02	5.96	−1034990	−1035031	140.30
4	−762106	−7.91	−0.61	−7.80	−0.84	7.10	−761954	−761993	131.58
5	−1163613	−8.16	−1.16	−7.78	−1.14	9.58	−1163402	−1163457	182.46
6	−867806	−8.4	−0.99	−8.17	−1.00	3.42	−867646	−867690	145.88