Synthesis of podophyllotoxin-naphthoquinone compounds via microwave-assisted three-component reactions^a.

Entry	Product	Ar	Time (min)	Yieldb (%)	Mpc (°C)
1	5a	3-OMePh	15	86	290–293d
2	5b	3-BrPh	15	83	328–329d
3	5c	3-NO2Ph	15	75	283–285d
4	5d	Ph	15	84	329–334d
5	5e	4-MePh	15	88	320–322d
6	5f	2-NO2Ph	15	73	289–292d
7	5g	3-Oxo-1,3-dihydro benzofuran-5-yl	15	85	295–296d
8	5h	2-OHPh	20	80	311–312
9	5i	4-OHPh	20	79	304–305
10	5j	4-NO2Ph	15	82	298–299
11	5k	4-CNPh	15	89	306–307
12	5l	3,4-(MeO)2Ph	15	85	288–289
13	5m	3,4,5-(MeO)3Ph	15	86	310–311
14	5n	Pyridin-3-yl	15	81	210–212
15	5o	5-Br-pyridin-2-yl	15	83	274–275

^aAll the reactions were carried out in 1 mmol scale in 3 mL solvent at 120 °C under MW at the maximum power of 150 W, and the ratio of 6/2/3 was 1/1/1.

^bIsolated yields.

^cDecomposed.

^dThese results were reported in our previous study.⁴⁶