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

Table 3

Relative energies and frontier orbital energies of the tautomers of molecules 2 (denoted as 2-1 and 2-2), 3 (3-1 and 3-2), and 6 (6-1) in the gas phase.

Tautomer	Relative energy (kJ/mol)	EHOMO (eV)	ELUMO (eV)	μ	η	ω	N	Dipole (debye)
2	0	−8.52	−0.94	−4.73	3.79	2.95	0.6	6.35
2-1	15.1	−8.64	−1.28	−4.96	3.68	3.34	0.48	4.33
2-2	18.07	−8.52	−1.08	−4.80	3.72	3.1	0.6	9.18
3	0	−8.52	−1.01	−4.77	3.755	3.02	0.6	5.96
3-1	18.5	−7.79	−1.42	−4.61	3.185	3.33	1.33	6.03
3-2	22.1	−7.83	−1.3	−4.57	3.265	3.19	1.29	9.92
6	0	−8.4	−0.99	−4.70	3.705	2.97	0.72	3.42
6-1	74.69	−7.47	−1.53	−4.50	2.97	3.41	1.65	3.81