N1-Furoyl-N1-(2-furyl)-N2-phenylurea 9k. Yield (10%; 20%
with Et3N), colourless crystals, mp 119–121 ЊC (Found: C,
64.58; H, 3.89; N, 9.18. C16H12N2O4 requires C, 64.86; H, 4.08;
N, 9.45%); νmax/cmϪ1 3235, 3138, 1730, 1659, 1597, 1557, 1464,
1279, 1173, 1129; δH (d6-DMSO) 5.85 (d, 1H, J 3.5 Hz, furyl
3-H), 6.25–6.50 (m, 2H, furyl 3Ј-H and 4-H), 6.55 (dd, 1H,
J 3.35 and 2.0 Hz, furyl 4Ј-H), 6.87–7.75 (m, 5H, ArH, furyl
N1-Acetyl-N1-[5-(4-bromophenyl)-2-furyl]-N2-phenylurea 9g.
Yield (12%; 35% with Et3N), colourless crystals, mp 142–144 ЊC
(Found: C, 56.95; H, 3.65; N, 6.85; Br, 19.83. C19H15BrN2O3
requires C, 57.16; H, 3.79; N, 7.02; Br, 20.01%); νmax/cmϪ1 3204,
3142, 3111, 3065, 3044, 1728, 1686, 1601, 1528, 1480, 1448,
1370, 1271, 1173; δH 2.18 (s, 3H, COCH3), 6.47 (d, 1H, J 3.4 Hz,
furyl 3-H), 6.75 (d, 1H, J 3.4 Hz, furyl 4-H), 6.94–7.75 (m, 5H,
+
ؒ
+
ؒ
5-H and 5Ј-H), 11.16 (br s, 1H, NH); m/z 296 (M ).
ArH), 7.52 (s, 4H, ArH), 11.03 (br s, 1H, NH); m/z 399 (M ).
N1-Acetyl-N1-(4,5-dimethyl-2-furyl)-N2-phenylurea 9h. Yield
(16%; 27% with Et3N), colourless crystals, mp 71–74 ЊC
(Found: C, 66.00; H, 5.78; N, 12.98. C15H16N2O3 requires C,
66.16; H, 5.92; N, 10.29%); νmax/cmϪ1 3245, 3189, 1732, 1686,
1599, 1595, 1547, 1447, 1372, 1316, 1306, 1271, 1235, 1217,
1190; δH 1.97 (s, 3H, CH3), 2.11 (s, 3H, COCH3), 2.23 (s, 3H,
CH3), 6.12 (s, 1H, furyl 3-H), 7.09 (t, 1H, ArH-4Ј), 7.30 (t, 2H,
ArH-3Ј,5Ј), 7.53 (d, 2H, ArH-2Ј,6Ј), 11.04 (br s, 1H, NH);
δC 9.92 (CH3), 11.26 (CH3), 24.82 (COCH3), 110.86 (C-3),
115.92 (C-4), 120.09 (C-2Ј,6Ј), 124.17 (C-4Ј), 128.85 (C-3Ј,5Ј),
137.31 (C-1Ј), 140.48 (C-5), 146.52 (C-2), 150.82 (NHCO),
N1-Acetyl-N1-(2-furyl)-N2-(4-methylphenyl)urea 9l. Yield
(16%), colourless crystals, mp 109–112 ЊC (Found: C, 64.95;
H, 5.28; N, 10.62. C14H14N2O3 requires C, 65.11; H, 5.46;
N, 10.85%); νmax/cmϪ1 3179, 3129, 3079, 3032, 1730, 1682, 1593,
1549, 1516, 1499, 1321, 1271, 1175, 1072, 1049; δH 2.07 (s, 3H,
COCH3), 2.30 (s, 3H, CH3), 6.36 (dd, 1H, J 3.15 and 0.8 Hz,
furyl 3-H), 6.49 (dd, 1H, J 3.15 and 2.2 Hz, furyl 4-H), 7.11
(d, 2H, J 8.5 Hz, ArH), 7.41 (d, 2H, J 8.5 Hz, ArH), 7.42 (dd,
1H, J 2.2 and 0.8 Hz, furyl 5-H), 10.96 (br s, 1H, NH); δC 20.77
(Ar-CH3), 24.74 (CO-CH3), 108.12 (C-3), 111.61 (C-4), 120.18
(C-2Ј, C-6Ј), 129.15 (C-3Ј, C-5Ј), 133.92 (C-4Ј), 134.64 (C-1Ј),
141.35 (C-5), 143.92 (C-2), 150.61 (NH-CO), 175.30 (CO-
+
ؒ
175.68 (CH3CO); m/z 272 (M ).
+
ؒ
CH3); m/z 258 (M ).
(iii) At 110 ؇C. N 2-Phenyl-5-phenylfuran-2-carboximidamide
8b. A solution of amidine 8b (0.33 g, 1.25 mmol) in toluene
(5 cm3) was added dropwise to a suspension of DAIB (0.4 g,
1.25 mmol) in toluene (5 cm3) and heated under reflux. After
evaporation, the residue was purified by column chroma-
tography (silica gel: CHCl3 as eluent). The major product was
crystallised from toluene and identified as N1-(phenyl-
(ii) At 60 ؇C. Using a procedure identical to that described
above using DAIB (without addition of Et3N), except that the
reaction flask was maintained at 60 ЊC, N2-phenyl-5-phenyl-
furan-2-carboximidamide 8b gave N1-acetyl-N1-(5-phenyl-2-
furyl)-N2-phenylurea 9b (19%), colourless crystals, mp 128–
130 ЊC (Found: C, 71.00; H, 4.85; N, 8.50. C19H16N2O3 requires
C, 71.24; H, 5.03; N, 8.74%); νmax/cmϪ1 3185, 3148, 3127, 3085,
3067, 3042, 1725, 1686, 1599, 1559, 1541, 1447, 1368, 1262,
1229, 1175, 1015; δH 2.17 (s, 3H, COCH3), 6.45 (d, 1H, J 3.5 Hz,
furyl 3-H), 6.73 (d, 1H, J 3.5 Hz, furyl 4-H), 6.88–7.75 (m, 10H,
carbamoyl)-N2-phenyl-5-phenylfuran-2-carboximidamide
11b
(0.1 g, 42%), colourless crystals, mp 210–213 ЊC (Found: C,
75.40; H, 4.82; N, 10.88. C24H19N3O2 requires C, 75.57; H, 5.02;
N, 11.02%); νmax/cmϪ1 3243, 3134, 1684, 1641, 1599, 1562, 1514,
1487, 1449, 1302, 1277; δH (d6-DMSO) 6.60–8.00 (m, 17H,
ArH, furyl 3-H, furyl 4-H), 9.45 (br s, 1H, NH), 9.52 (br s, 1H,
+
ؒ
ArH), 11.04 (br s, 1H, NH); m/z 320 (M ).
In a similar manner the following compounds were prepared
from amidines 8c–g respectively.
+
ؒ
NH); m/z 381 (M ).
In a similar manner the following compounds were prepared
from amidines 8c–g respectively.
N1-Acetyl-N1-[5-(4-chlorophenyl)-2-furyl]-N2-phenylurea 9c.
Yield (17%), colourless crystals, mp 190–193 ЊC (Found: C,
64.15; H, 4.05; N, 7.68; Cl, 9.70. C19H15ClN2O3 requires C,
64.32; H, 4.26; N, 7.90; Cl, 9.99%); νmax/cmϪ1 3202, 3137, 1725,
1597, 1557, 1537, 1482, 1446, 1368, 1267, 1174, 1092; δH 2.17
(s, 3H, COCH3), 6.46 (d, 1H, J 3.4 Hz, furyl 3-H), 6.73 (d, 1H,
J 3.4 Hz, furyl 4-H), 6.88–7.88 (m, 9H, ArH), 11.03 (br s, 1H,
N1-(Phenylcarbamoyl)-N2-phenyl-5-(4-chlorophenyl)furan-
2-carboximidamide 11c. Yield (43%), light yellow crystals, mp
216–218 ЊC (Found: C, 69.15; H, 4.10; N, 10.00. C24H18ClN3O2
requires C, 69.31; H, 4.36; N, 10.10%); νmax/cmϪ1 3262, 3130,
1682, 1640, 1597, 1556, 1512, 1485, 1448, 1298, 1281; δH (d6-
DMSO) 6.60–8.00 (m, 16H, ArH), 9.48 (br s, 1H, NH), 9.53 (br
+
ؒ
+
ؒ
NH); m/z 354 (M ).
s, 1H, NH); m/z 415 (M ).
N1-Acetyl-N1-[5-(4-nitrophenyl)-2-furyl]-N2-phenylurea 9d.
Yield (21%), light yellow crystals, mp 240–242 ЊC (Found: C,
62.30; H, 3.98; N, 11.25. C19H15N3O5 requires C, 62.46; H, 4.14;
N, 11.50%); νmax/cmϪ1 3256, 3196, 3133, 3111, 1725, 1690, 1593,
1561, 1541, 1508, 1448, 1369, 1267, 1174; δH 2.20 (s, 3H,
COCH3), 6.56 (d, 1H, J 3.5 Hz, furyl 3-H), 6.97 (d, 1H, J 3.5
Hz, furyl 4-H), 7.00–8.13 (m, 5H, ArH), 7.79 (d, 2H, J 8.7 Hz,
ArH), 8.26 (d, 2H, J 8.7 Hz, ArH), 11.01 (br s, 1H, NH);
N1-(Phenylcarbamoyl)-N2-phenyl-5-(4-nitrophenyl)furan-2-
carboximidamide 11d. Yield (40%), yellow needles, mp 205–
208 ЊC (Found: C, 67.40; H, 4.10; N, 12.98. C24H18N4O4
requires C, 67.60; H, 4.25; N, 13.14%); νmax/cmϪ1 3245, 3133,
1684, 1638, 1599, 1559, 1516, 1485, 1447, 1337, 1279; δH
(d6-DMSO) 6.70–8.25 (m, 16H, ArH), 9.58 (br s, 2H, 2NH);
+
ؒ
m/z 426 (M ).
N1-(Phenylcarbamoyl)-N2-phenyl-5-(4-methylphenyl)furan-
2-carboximidamide 11e. Yield (45%), beige crystals, mp 205–
208 ЊC (Found: C, 75.70; H, 5.15; N, 10.40. C25H21N3O2
requires C, 75.93; H, 5.35; N, 10.63%); νmax/cmϪ1 3268, 3129,
1680, 1638, 1595, 1559, 1522, 1489, 1447, 1308, 1298, 1279,
1230, 1136; δH (d6-DMSO) 2.21 (s, 3H, CH3), 6.60–8.00 (m,
16H, ArH), 9.43 (br s, 1H, NH), 9.51 (br s, 1H, NH); m/z 395
+
ؒ
m/z 365 (M ).
N1-Acetyl-N1-[5-(4-methylphenyl)-2-furyl]-N2-phenylurea 9e.
Yield (15%), colourless crystals, mp 125–128 ЊC (Found: C,
71.68; H, 5.28; N, 8.25. C20H18N2O3 requires C, 71.84; H, 5.43;
N, 8.38%); νmax/cmϪ1 3181, 3137, 3077, 3034, 1725, 1686, 1601,
1560, 1552, 1498, 1446, 1372, 1269, 1173, 1019; δH 2.17 (s, 3H,
COCH3), 2.36 (s, 3H, CH3), 6.43 (d, 1H, J 3.4 Hz, furyl 3-H),
6.67 (d, 1H, J 3.4 Hz, furyl 4-H), 7.04–7.70 (m, 9H, ArH), 11.18
+
ؒ
(M ).
N1-(Phenylcarbamoyl)-N2-phenyl-5-(4-methoxyphenyl)-
furan-2-carboximidamide 11f. Yield (38%), light yellow crystals,
mp 204–206 ЊC (Found: C, 72.70; H, 5.00; N, 10.00. C25H21-
N3O3 requires C, 72.98; H, 5.14; N, 10.21%); νmax/cmϪ1 3237,
3135, 1682, 1638, 1597, 1557, 1487, 1449, 1298, 1277, 1256;
δH (d6-DMSO) 3.68 (s, 3H, OCH3), 6.50–8.00 (m, 16H, ArH),
+
ؒ
(br s, 1H, NH); m/z 334 (M ).
N1-Acetyl-N1-[5-(4-methoxyphenyl)-2-furyl]-N2-phenylurea
9f. Yield (15%), colourless crystals, mp 142–144 ЊC (Found:
C, 68.35; H, 4.98; N, 7.88. C20H18N2O4 requires C, 68.56; H,
5.18; N, 8.00%); νmax/cmϪ1 3202, 3131, 3061, 3015, 1730, 1686,
1618, 1601, 1543, 1498, 1446, 1365, 1267, 1250, 1179, 1022;
δH 2.18 (s, 3H, COCH3), 3.83 (s, 3H, OCH3), 6.42 (d, H, J 3.4
Hz, furyl 3-H), 6.60 (d, 1H, J 3.4 Hz, furyl 4-H), 6.91 (d, 2H,
J 8.9 Hz, ArH), 7.04–7.70 (m, 5H, ArH), 7.59 (d, 2H, J 8.9 Hz,
+
ؒ
9.41 (br s, 1H, NH), 9.48 (br s, 1H, NH); m/z 411 (M ).
N1-(Phenylcarbamoyl)-N2-phenyl-5-(4-bromophenyl)furan-
2-carboximidamide 11g. Yield (40%), light yellow crystals, mp
215–218 ЊC (Found: C, 62.40; H, 3.80; N, 9.00. C24H18BrN3O2
requires C, 62.62; H, 3.94; N, 9.13%); νmax/cmϪ1 3264, 3131,
+
ؒ
ArH), 11.06 (br s, 1H, NH); m/z 350 (M ).
686
J. Chem. Soc., Perkin Trans. 1, 2001, 680–689