Gas Chromatography Electron Ionization Mass Spectral Analysis of Thio Analogues of Pyrimidine Bases: 5-Bromo-2,4-di-o-(m- and p-) chloro- (bromo-)benzylthiouracils and 6-methyluracils

Table 1

Elemental compositions and relative abundances of the ion peaks in the spectra of 1–6 according to the high-resolution data.

Ion	m/z	Elemental composition	% relative abundance (%RA)
			1	2	3	4	5	6
M^+ ^•	470/472/474	C18H13N2S2Cl2Br	13/20/13	23/42/23	12/24/16	—	—	—
a	558/560/562/564	C18H13N2S2Br3	—	—	—	9/30/23/8	15/31/34/17	13/37/38/13
b [a– ^•SH]	437/439/441	C18H12N2SCl2Br	27/14/3	6/14/5	6/5/4
	525/527/529/531	C18H12N2SBr3				1/5/6/2	6/7/12/5	2/10/9/3
c [a– ^•X]	435/437/439	C18H13N2S2ClBr	21/27/14	0.6/6/14	0.9/6/5
	479/481/483	C18H13N2S2Br2				25/44/27	6/14/9	2/2/2
d [a– ^•SH– ^•X]	402/404/406	C18H12N2SClBr	3/4/1	2/5/3	2/2/3	—	—	—
	446/448/450	C18H12N2SBr2	—	—	—	5/18/6	7/11/4	5/14/4
d′ [a– ^•SH–HX]	401/403/405	C18H11N2SClBr	5/7/3	5/10/4	3/8/4
	445/447/449	C18H11N2SBr2				2/12/3	10/21/11	13/27/15
e	345/347/349	C11H7N2S2ClBr	18/25/9	32/42/14	21/24/7	—	—	—
	389/391/393	C11H7N2S2Br2	—	—	—	13/54/18	25/61/38	27/48/27
f [e– ^•X]	310/312	C11H7N2S2Br	19/20	5/13	1/9	53/68	10/13	6/6
g	125/127	C7H6Cl	100/36	100/33	100/33	—	—	—
	169/171	C7H6Br	—	—	—	100/99	72/70	99/100
h	90	C7H6	11	15	7	99	100	79
j	89	C7H5	58	58	42	85	73	72