Stereochemical Investigations of Diastereomeric N-[2-(Aryl)-5-methyl-4-oxo-1,3-thiazolidine-3-yl]-pyridine-3-carboxamides by Nuclear Magnetic Resonance Spectroscopy (1D and 2D)

Table 1

¹H NMR (500 MHz) data of compounds 2a–2f in .

Entry	C-6 methyl	C-5 methine	C-2 methine	CO-NH
2a	1.55 (d,  Hz)	4.13 (qd,  Hz, 0.97 Hz); 4.23 (qd, , 1.47 Hz)	5.92 (s)	10.94 (s)
2b	1.54 (d, ); 1.55 (d,  Hz)	4.12 (q,  Hz); 4.22 (q,  Hz)	5.90 (s)	10.94 (s); 10.95 (s)
2c	1.55 (d,  Hz); 1.57 (d,  Hz)	4.15 (q,  Hz); 4.25 (qd, , 1.47 Hz)	6.01 (d,  Hz); 6.02 (s)	10.99 (s); 11.01 (s)
2d	1.53 (d,  Hz); 1.55 (d,  Hz)	4.10 (q,  Hz); 4.16 (qd, , 1.47 Hz)	5.87 (s); 5.88 (d,  Hz)	10.90 (s)
2e	1.54 (d, ); 1.55 (d,  Hz)	4.11 (q,  Hz); 4.18 (qd, , 1.46 Hz)	5.89 (s); 5.90 (s)	10.97 (s)
2f	1.48 (d, ); 1.52 (d,  Hz)	4.10 (q,  Hz); 4.21 (qd, , 1.96 Hz)	6.22 (d,  Hz); 6.26 (s)	11.04 (s); 11.05 (s)

For ¹H NMR data of the other protons, see Section 2.
The signals corresponding to major diastereomer.
Coupling with C-2 methine was observed as a shoulder.