ACCEPTED MANUSCRIPT
(219.22): C, 54.79; H, 4.60; N, 31.95; Found: C, 54.61; H, 4.63; N, 32.12. Hydrochloride 7a. Mp 217–
219 °C; IR (KBr, cm-1) 3102, 2903, 2613, 1650, 1514, 1289, 995, 775. Anal. calcd. for C10H11ClFN5
(255.68): C, 46.98; H, 4.34; N, 27.39. Found: C, 46.90; H, 4.16; N, 27.36.
4.1.4.2. 5-Fluoro-1-[(imidazolidin-2-yl)imino]-1H-indazole (6b). Yield: 0.45 g (63 %); IR (KBr, cm-1)
3344, 3239, 3170, 2967, 2896, 1632, 1500, 1288, 1129, 796; 1H NMR (CDCl3, 200 MHz) δ 3.59 (s, 4H),
5.50 (br s, 1H), 6.35 (br s, 1H), 7.09 (dt, J1=8.8 Hz, J2=2.2 Hz, 1H), 7.26 (dd, J1=8.8 Hz, J2=2.2 Hz, 1H),
7.46 (dd, J1=9.2 Hz, J2=4.4 Hz, 1H), 7.77 (s, 1H); 13C NMR (CDCl3, 50 MHz) δ 42.6 (br s), 104.3 (d, J=24
Hz), 111.6 (d, J=9.6 Hz), 116.0 (d, J=27.7 Hz), 128.3 (d, J=6 Hz), 133.8, 158.5 (d, J=238 Hz), 162.1. Anal.
calcd. for C10H10FN5 (219.22): C, 54.79; H, 4.60; N, 31.95; Found: C, 54.86; H, 4.23; N, 31.86.
Hydrochloride 7b. Mp 215–217 °C; IR (KBr, cm-1) 3118, 2933, 1655, 1626, 1513, 1215. Anal. calcd. for
C10H11ClFN5 (255.68): C, 46.98; H, 4.34; N, 27.39. Found: C, 47.12; H, 4.49; N, 27.22.
4.1.4.3. 6-Fluoro-1-[(imidazolidin-2-yl)imino]-1H-indazole (6c). Yield: 0.52 g (73 %); mp 182–184 °C; IR
(KBr, cm-1) 3248, 3162, 2999, 2886, 2808, 1635, 1618, 1473, 1289, 1203, 952, 839. 1H NMR (DMSO-d6,
200 MHz) δ 3.38 (br s), 6.48 (br s, 1H), 6.68 (br s, 1H), 6.89–7.02 (m, 2H), 7.73 (dd, J1= 5.1 Hz, J2= 8.3
Hz, 1H), 7.91 (s, 1H). 13C NMR (DMSO-d6, 50 MHz) δ 42.6, 43.7, 95.7 (d, J=26.3 Hz), 110.5 (d, J=26.5
Hz), 119.6, 123.4 (d, J=11.1 Hz), 129.2, 136.7, 161.8 (d, J=240.8 Hz), 165.1. Anal. calcd. for C10H10FN5
(219.22): C, 54.79; H, 4.60; N, 31.95; Found: C, 54.91; H, 4.66; N, 31.73. Hydrochloride 7c. Mp 202–
204 °C; IR (KBr, cm-1) 3194, 2926, 1648, 1624, 1477, 1215, 950. Anal. calcd. for C10H11ClFN5 (255.68):
C, 46.98; H, 4.34; N, 27.39. Found: C, 46.99; H, 4.16; N, 27.51.
4.1.4.4. 7-Fluoro-1-[(imidazolidin-2-yl)imino]-1H-indazole (6d). Yield 0.49 g (70 %); mp 253–255 °C; IR
(KBr, cm-1) 3243, 3167, 3060, 3012, 2878, 2842, 1632, 1519, 1289, 1214, 1069, 729; H1 NMR (DMSO-
d6, 200 MHz) δ 3.31 (br s, 4H), 6.38 (br s, 1H), 6.72 (br s, 1H), 6.95–7.09 (m, 2H), 7.51 (d, J=7.8 Hz,
1H), 7.95 (d, J=2.0 Hz, 1H); 13C NMR (DMSO-d6, 50 MHz) δ 41.3, 42.2, 109.4 (d, J=16.8 Hz), 116.2 (d,
J=4.5 Hz), 119.5 (d, J=5.4 Hz), 125.5 (d, J=4.2 Hz), 128.2, 147.5 (d, J=249 Hz), 164.8. Anal. calcd. for
C10H10FN5 (219.22): C, 54.79; H, 4.60; N, 31.95; Found: C, 55.10; H, 4.28; N, 32.16. Hydrochloride 7d.
Mp 228–230 °C; IR (KBr, cm-1) 3297, 3099, 2888, 1655, 1628, 1214, 1070, 859, 734. Anal. calcd. for
C10H11ClFN5 (255.68): C, 46.98; H, 4.34; N, 27.39. Found: C, 46.73; H, 4.50; N, 27.14.
4.1.4.5. 4,5,6,7-Tetrafluoro-1-[(imidazolidin-2-yl)imino]-1H-indazole (6e). Obtained from 0.047 g (0.1
mmol) of 5e and 0.4 ml of 50% TFA in CH2Cl2. Yield 0.024 g (88 %); mp 210–212 °C; IR (KBr, cm-1)
3332, 3254, 3184, 1634, 1547, 1489, 1345, 955; 1H NMR (200 MHz, CDCl3) δ 3.64 (br s, 4H), 5.02 (br s,
1H), 6.18 (br s, 1H), 7.95 (d, J=1.5 Hz, 1H); 13C NMR (50 MHz, CDCl3) δ 42.2 (br s), 43.6 (br s), 162.2 (d,
J=6.5 Hz), 137.3, 162.4. The other signals could not be detected due to their high multiplicity and
thus low intensity. Anal. calcd. for C10H7F4N5 (273.19): C, 43.96; H, 2.58; N, 25.64. Found: C, 44.13; H,
2.37; N, 25.79. Hydrochloride 7e. Mp 216–218 °C; IR (KBr, cm-1) 3075, 3003, 2876, 1648, 1533, 1488,
1349, 944. Anal. calcd. for C10H8ClF4N5 (309.65): C, 38.79; H, 2.60; N, 22.62. Found: C, 38.88; H, 2.64;
N, 2.37.
4.1.5. The general procedure for the synthesis of fluoro-1-[(4,5-dihydro-1H-imidazol-2-yl)methyl]-1H-
indazoles 8a–c and their hydrochloride salts 10a–c.
The title compounds were obtained according to a method described by J. Sączewski et al.
[48]. To the stirred solution of properly substituted fluoroindazole (0.5 g, 3.7 mmol) in anhydrous THF
(5 ml) sodium hydride (0.22 g, 5.5 mmol, 60 % oil dispersion) was added in one portion. After 15 min.