Table 1.

The yields, colours, and ESI-MS data of Cds. 1–7.

	Cd. 1	Cd. 2	Cd. 3	Cd. 4	Cd. 5	Cd. 6	Cd. 7
Yield (%)	53.2	48.3	45.1	65.3	41.3	66.3	69.6
Color	White powder	White powder	Yellow needle crystal	White needle crystal	Yellow powder	While needle crystal	Light yellow powder
m.p. (°C)	>244 a	180–181	229–230	164–165	>200 a	162–163	178–180
ESI-MS (m/z)	238.05 b	250.08 c	264.07 c	292.3 c	286.2 c	318.3 c	312.3 c

^a Decomposing temperature; ^b [M + 1]⁺; ^c [M − 1]⁻.