Table III.

Synthesis and Characterization of Xanthine Derivatives

compd	% yield	mp, °C	formula	anal.
13	91	278	C12H16N4OS	C, H, N
14	89	217	C16H24N4OS	C, H, N
15a	80	347	C11HI0N4O3	C, H, N
15b	88	252	C15H18N4O3	C, H, N
15c	85	>350	C11H10N4O2S	C, H, N
15d	88	269	C15H18N4O2S	C, H, N
17	82	>300	C11H10N4O2S	C, H, N
18	92	>300	C11H10N4O2S	C, H, N
19	85	259	C15H18N4O2S	C, H, N
20	87	267	C15H18N4O2S	C, H, N
21	71	>340	C11H10N4O2S2	C, H, N
22	92	298	C15H18N4OS2	C, H, N
26a	91	>350	C13H12N4OS	C, H, N
26b	80	253	C17H20N4OS	C, H, N
33	95	206–208	C22H30N6O3S·¼H2O	C, H, N
35	93	238–240	C23H32N6O3S·¾H2O	C, H, N
37	52	172–174	C24H34N6O3S·½H2O	C, H, N
39	92	210–212	C40H54N8O8S	C, H, N
41	84	182–187	C37H47F3N8O8S·½CF3COOH·½H2O	C, H, N
43	97	238–242 dec	C27H40N8O4S·3HBr·3/2H2O	C, H, N
45	68	160–168	C33H43N7O8S	C, H, Nb
48	85	240 dec	C27H31N6O5SI·2.5H2O	C, H, N
52	85	236	C12H16N4S2	C, H, N
53	84	135	C16H24N4S2	C, H, N
54	79	241	C12H16N4OS	C, H, N
55	81	153	C10H24N4OS	C, H, N
56	84	256	C13H12N4OS	C, H, N
57	72	223	C15H16N4OS	H, C, Na
60b	84	230	C11H9NO3SHg	C, H, N
61a	43	71–73	C6H5O2SI·0.5H2O	C, H

^aC: calcd, 59.32; found, 58.52. N: calcd, 18.65; found, 18.12.

^bN: calcd, 14.05; found, 15.42.