3518
R. AL-SALAHI AND D. GEFFKEN
CH2), 7.68–8.39 (m, 4H, Ar-H); 13C NMR (DMSO-d6, d ppm): 12.92 (CH3), 52.74
(CH2), 57.18 (SCH3), 114.73, 116.22, 125.71, 128.79, 133.20, 135.02 (Ar-C), þ148.49
=
(C-guanidine), 157.34 (C O), 167.89 (C-isothiourea). MS, m=z (%): 260 (M , 88).
Anal. calcd. for C12H12N4OS: C, 55.37; H, 4.65; N, 21.52; S, 12.32. Found: C,
55.30; H, 4.62; N, 21.61; S, 12.25.
4-Allyl-2-methylsulfanyl[1,2,4]triazolo[1,5-a]quinazolin-5-one (6c). Mp
ꢀ1
1
130–132 ꢁC. IR spectrum (KBr, n, cm ): 1679 (C O); H NMR (DMSO-d6, d
ppm): 4.03 (s, 3H, CH3), 4.73 (d, 2H, J ¼ 4.70 Hz, -CH2 ¼ CH-CH2), 5.24–5.28 (m,
2H, -CH2 ¼ CH-CH2), 6.09–6.24 (m, 1H, -CH2 ¼ CH-CH2), 7.46–8.31 (m, 4H,
Ar-H); 13C NMR (DMSO-d6, d ppm): 45.53 (-CH2 ¼ CH-CH2), 57.34 (CH3),
114.27 (Ar-C), 116.78 (-CH2 ¼ CH-CH2), 117.28, 125.83, 128.82, 132.86 (Ar-C),
=
=
135.42 (-CH2 ¼ CH-CH2), 135.86 (Ar-C), 148.79 (C-guanidine), 156.89 (C O),
166.73 (C-isothiourea). MS, m=z (%): 272 (Mþ, 90). Anal. calcd. for C13H12N4OS:
C, 57.34; H, 4.44; N, 20.57; S, 11.77. Found: C, 57.25; H, 4.41; N, 20.49; S, 11.83.
4,5-Dihydro-2-methylsulfanyl[1,2,4]triazolo[1,5-a]quinazoline (7)
A solution of compound 5 (0.001 mol) in dry THF (5 mL) was added dropwise
to a stirred suspension of LiAlH4 (0.003 mol) in dry THF (10 mL). After stirring at
room temperature for 3 h, water (0.4 mL) was added carefully, and the mixture was
stirred for an additional 30 min. The reaction mixture was filtered, and the solvent
was removed under reduced pressure. The residue was dissolved in THF and passed
through short column chromatography, the solvent was removed under reduced
pressure, and the obtained solid was recrystallized from ethyl acetate=n-hexane to
1
give compound 7 (0.155 g, 71%), mp 126–128 ꢁC. H NMR (DMSO-d6, d ppm):
3.80 (s, 3H, CH3), 4.25 (s, 2H, CH2-quinazoline), 7.15–7.63 (m, 4H, Ar-H), 7.85
(s, 1H, NH); 13C NMR (DMSO-d6, d ppm): 13.05 (CH3), 69.00 (CH2-quinazoline),
114.23, 119.64, 124.50, 126.23, 130.75, 149.79 (Ar-C), 158.60 (C-guanidine), 161.86
(C-isothiourea). MS, m=z (%): 218 (Mþ, 100). Anal. calcd. for C10H10N4S: C,
55.03; H, 4.62; N, 25.67; S, 14.69. Found: C, 55.10; H, 4.59; N, 25.75; S, 14.82.
2-Methylsulfanyl-4H-[1,2,4]triazolo[1,5-a]quinazolin-5-thione (8)
Compound
5 (0.001 mol) was refluxed with phosphorus pentasulfide
(0.001 mol) in absolute pyridine (5 mL) for 2 h. Afterward, the reaction mixture
was cooled and poured into ice water, and the yellow precipitate was separated by
filtration and washed thoroughly with water. Recrystallization from aqueous
dimethyl formamide furnished analytically pure 9 (0.225 g, 91%), mp 230–232 ꢁC.
1
IR (KBr, n, cmꢀ1): 1264 (C S); H NMR (DMSO-d6, d ppm): 2.92 (s, 3H, CH3),
=
7.72–8.96 (m, 4H, Ar-H), 14.62 (s,1H, NH); 13C NMR (DMSO-d6, d ppm): 13.95
(CH3), 114.65, 122.43, 125.83, 131.77, 132.01, 132.23 (Ar-C), 141.28 (C-guanidine),
=
163.18 (C-isothiourea), 185.61 (C S). MS, m=z (%): 248 (M , 100). Anal. calcd.
þ
for C10H8N4S2: C, 48.37; H, 3.25; N, 22.56; S, 25.82. Found: C, 48.32; H, 3.25; N,
22.47; S, 25.91.