L. Varga et al. / Tetrahedron 59 (2003) 655–662
661
1.2.2. 2-Amino-5-furan-2-yl-5-furan-2-ylmethyl-3,5-
dihydro-imidazol-4-one (8b). The experimental pro-
cedure was similar to that described for compound 8a
starting from 1,3-di-furan-2-yl-propenone (3, Ar1¼Ar2¼
furan-2-yl).
was similar to that described for compound 8a starting from
3-(4-methoxy-phenyl)-1-phenyl-propenone (3, Ar1¼C6H5,
Ar2¼4-CH3O–C6H4).
Compound 8e (64%, whitish solid), mp 304–3118C (deg.);
nmax (KBr): 3353 (nNH), 1700 (nCvOlactam), 1652
(nCvN), 1611, 1511 (nCArCAr), 696, 648 (aromatic ring
def.) cm21; dH (DMSO-d6) 3.02 (1H, d, J¼14 Hz, CH2-A),
3.23 (1H, d, J¼14 Hz, CH2-B), 3.70 (3H, s, OCH3), 6.75
(2H, m, Ar2H-3þAr2H-5), 6.8-7.4 (2H, brs, NH2), 7.08 (2H,
m, Ar2H-2þAr2H-6), 7.28 (1H, m, Ar1H-4), 7.38 (2H, m,
Ar1H-3þAr1H-5), 7.55 (2H, m, Ar1H-2þAr1H-6), 8.2 (1H,
brs, N3-H); dC (DMSO-d6) 42.6 (–CH2–), 54.8 (OCH3),
70.5 (C-5), 113.0 (Ar2C-3þAr2C-5), 125.4 (Ar1C-2þAr1C-6),
126.9 (Ar1C-4), 127.9 (Ar2C-1), 128.0 (Ar1C-3þAr1C-5),
131.1 (Ar2C-2þAr2C-6), 141.1 (Ar1C1), 157.9 (Ar2C-4),
170.4 (C-2), 188.0 (C-4); HPLC purity (220 nm): 99%;
HRMS (ES): calculated for C17H18N3O2 [(MþH)þ]
296.13988, found 296.1399.
Compound 8b (29%, whitish solid), mp 232–2348C (deg.);
nmax (KBr): 3354 (nNH), 1708 (nCvOlactam), 1653
(nCvN), 1564, 1488 (nCArCAr) cm21; dH (DMSO-d6)
3.23 (1H, d, CH2Fig. 2A), 3.33 (1H, d, CH2-B), 6.06 (1H,
Ar2H-3), 6.32 (1H, Ar2H-4), 6.37 (1H, Ar1H-3), 6.40 (1H,
Ar1H-4), 7.0 (1H, brs, NH2), 7.47 (1H, Ar2H-5), 7.59 (1H,
Ar1H-5), 7.6 (1H, brs, NH2), 8.19 (1H, s, N3-H); dC (DMSO-
d6) 33.2 (–CH2–), 66.0 (C-5), 106.7 (Ar1C-3), 107.8 (Ar2C-
3), 110.6 (Ar1C-4þAr2C-4), 142.0 (Ar2C-5), 142.6 (Ar1C-5),
150.4 (Ar2C-2), 152.8 (Ar1C-2), 171.6 (C-2), 186.0 (C-4);
HPLC purity (220 nm): 98%; HRMS (ES): calculated for
C12H12N3O3 [(MþH)þ] 246.08784, found 246.0876.
1.2.3. 2-Amino-5-thiophen-2-yl-5-thiophen-2-ylmethyl-
3,5-dihydro-imidazol-4-one (8c). The experimental
procedure was similar to that described for compound 8a
starting from 1,3-di-thiophen-2-yl-propenone (3, Ar1¼
Ar2¼thiophen-2-yl).
1.2.6. 2-Amino-5-(3,4-dimethoxy-benzyl)-5-phenyl-3,5-
dihydro-imidazol-4-one (8f). The experimental pro-
cedure was similar to that described for compound 8a
starting from 3-(3,4-dimethoxy-phenyl)-1-phenyl-pro-
penone [3, Ar1¼C6H5, Ar2¼3,4-(CH3O)2–C6H4].
Compound 8c (29%, whitish solid), mp 307–3108C (deg.);
nmax (KBr): 3357 (nNH), 3069 (nCArH), 1706
(nCvOlactam), 1655 (nCvN), 1561, 1489 (nCArCAr), 699
(aromatic ring def.) cm21; dH (DMSO-d6) 3.37 (1H, d,
J¼14 Hz, CH2-A), 3.49 (1H, d, J¼14 Hz, CH2-B), 6.86
(1H, dd, J¼3.5þ1 Hz, Ar2H-3), 6.90 (1H, dd, J¼5þ3.5 Hz,
Ar2H-4), 7.07.8 (2H, brs, NH2), 7.00 (1H, dd, J¼5þ4 Hz,
Ar1H-4), 7.08 (1H, dd, J¼4þ1.5 Hz, Ar1H-3), 7.30 (1H, dd,
J¼5þ1 Hz, Ar2H-5), 7.41 (1H, dd, J¼5þ1.5 Hz, Ar1H5),
8.45 (1H, s, N3-H); dC (DMSO-d6) 39.0 (–CH2–), 69.4
(C-5), 124.4 (Ar2C-5), 125.5 (Ar2C-3), 125.7 (Ar1C-5), 127.1
Compound 8f (60%, whitish solid), mp 306–3098C (deg.);
nmax (KBr): 3347 (nNH), 3064 (nCArH), 1701
(nCvOlactam), 1664 (nCvN), 1616, 1516 (nCArCAr)
cm21; dH (DMSO-d6) 3.02 (1H, d, J¼13.5 Hz, CH2-A),
3.19 (1H, d, J¼13.5 Hz, CH2-B), 3.64þ3.70 (2£3H, 2£s,
2£OCH3), 6.66 (1H, dd, J¼8þ2 Hz, Ar2H-6), 6.74 (1H, d,
J¼2 Hz, Ar2H-2), 6.76 (1H, d, J¼8 Hz, Ar2H-5), 6.8–7.4
(2H, brs, NH2), 7.26 (1H, m, Ar1H-4), 7.35 (2H, m, Ar1H-
3þAr1H5), 7.53 (2H, m, Ar1H-2þAr1H-6), 8.2 (1H, brs, N3-
H); dC (DMSO-d6) 43.2 (–CH2–), 55.3 (2£OCH3), 70.5
(C-5), 111.1 (Ar2C-5), 114.2 (Ar2C-6), 122.2 (Ar2C-2), 125.5
(
Ar1C-3), 127.6 (Ar1C-4), 128.0 (Ar2C-4), 137.6 (Ar2C-2),
145.3 (Ar1C-2), 171.7 (C-2), 187.3 (C-4); HPLC purity
(220 nm): 100%; HRMS (ES): calculated for C12H12N3OS2
[(MþH)þ] 278.04216, found 278.0425.
(
Ar1C-2þAr1C-6), 126.9 (Ar1C-4), 127.9 (Ar1C-3þAr1C-5),
128.4 (Ar2C-1), 141.1 (Ar1C1), 147.5 (Ar2C-3), 147.8 (Ar2C-
4), 170.5 (C-2), 188.0 (C-4); HPLC purity (220 nm): 97%;
HRMS (ES): calculated for C18H20N3O3 [(MþH)þ]
326.15044, found 326.1515.
1.2.4. 2-Amino-5-furan-2-ylmethyl-5-phenyl-3,5-di-
hydro-imidazol-4-one (8d). The experimental procedure
was similar to that described for compound 8a starting from
3-furan-2-yl-1-phenyl-propenone (3, Ar1¼C6H5, Ar2¼
furan-2-yl).
1.2.7. 2-Amino-5-(2-methoxy-benzyl)-5-phenyl-3,5-di-
hydro-imidazol-4-one (8g). The experimental procedure
was similar to that described for compound 8a starting from
3-(2-methoxy-phenyl)-1-phenyl-propenone [3, Ar1¼C6H5,
Ar2¼2-(CH3O)-C6H4].
Compound 8d (56%, whitish solid), mp ,2288C (deg.);
nmax (KBr): 3362 (nNH), 1703 (nCvOlactam), 1651
(nCvN), 1494 (nCArCAr), 697 (aromatic ring def.) cm21
;
Compound 8g (43%, whitish solid), mp 306–3098C (deg.);
nmax (KBr): 3369 (nNH), 1701 (nCvOlactam), 1658
(nCvN), 1587, 1493 (nCArCAr), 753 (gCArH), 697
(aromatic ring def.) cm21; dH (DMSO-d6) 3.18 (1H, d,
J¼14 Hz, CH2-A), 3.31 (1H, d, J¼14 Hz, CH2-B), 3.75
(3H, s, OCH3), 6.6–7.6 (2H, brs, NH2), 6.77 (1H, dd,
J¼8þ7.5 Hz, Ar2H-5), 6.9 (1H, d, J¼7 Hz, Ar2H-3), 6.99
(1H, d, J¼8 Hz, Ar2H-6), 7.18 (1H, dd, J¼7.5þ7 Hz, Ar2H-
4), 7.28 (1H, m, Ar1H-4), 7.34 (2H, m, Ar1H-3þAr1H-5), 7.50
(2H, m, Ar1H-2þAr1H-6), 7.7 (1H, s, N3-H); dC (DMSO-d6)
37.1 (–CH2–), 55.4 (OCH3), 70.1 (C-5), 110.6 (Ar2C-3),
119.9 (Ar2C-5), 124.2 (Ar2C-1), 125.3 (Ar1C-2þAr1C-6),
126.9 (Ar1C-4), 127.9 (Ar1C-3þAr1C-5þAr2C-6), 130.8
dH (DMSO-d6) 3.28 (1H, d, CH2-A), 3.37 (1H, d, CH2-B),
5.98 (1H, Ar2H-3), 6.22 (1H, Ar2H-4), 7.23 (1H, Ar1H-4),
7.32 (2H, Ar1H-3þAr1H-5), 7.44 (1H, Ar2H-5), 7.51 (2H,
Ar1H-2þAr1H-6), ,7.3 (2H, br, NH2), 8.32 (1H, s, N3-H);
dC (DMSO-d6) 36.3 (–CH2–), 69.1 (C-5), 107.7 (Ar2C-4),
110.6 (Ar2C-3), 125.5 (Ar1C-3þAr1C-5), 127.2 (Ar1C-4),
128.2 (Ar1C-2þAr1C6), 140.4 (Ar1C-1), 141.9 (Ar2C-5),
151.0 (Ar2C-2), 171.2 (C2), 187.9 (C-4); HPLC purity
(220 nm): 96%; HRMS (ES): calculated for C14H14N3O2
[(MþH)þ] 256.10858, found 256.1084.
1.2.5. 2-Amino-5-(4-methoxy-benzyl)-5-phenyl-3,5-di-
hydro-imidazol-4-one (8e). The experimental procedure
(
Ar2C-4), 141.1 (Ar1C1), 157.6 (Ar2C-2), 170.9 (C-2), 188.1