Table 1.

Experimental conditions used for the optimization of caffeine selenation with WR under microwave irradiation.

WR (µmol)	Solvent	Irradiation Time (min)	Max. Temp. (°C)	Irradiation potency (W)	2 ɳ (%)
103	acetonitrile	5	150	175	4
206		5	150	175	n.r. a
103		5	130	200	n.r. a
206		10	130	200	n.r. a
103		5	130	175	2
103		5	150	250	3
103		10	150	250	5
103		5	170	300	2
103	toluene	50	170	300	7
103		90	170	300	17
206		180	170	300	23
206		180	170	300	30
156	p-xylene	180	170	300	42
206	1,4-dioxane	180	170	300	19
206	propionitrile	180	170	300	21

^a n.r. no reaction.