The Journal of Organic Chemistry
Note
4.5 Hz, 1H), 3.78 (d, J = 13.4 Hz, 1H), 3.73 (s, 1H), 3.47 (d, J = 13.4
Hz, 1H), 2.74 (dt, J = 7.5, 4.1 Hz, 1H), 1.91 (s, 2H), 1.41 1.25 (m,
3H), 1.15 (dd, J = 13.3, 6.5 Hz, 1H), 0.78 (t, J = 6.8 Hz, 3H); 13C
NMR (75 MHz, CDCl3) δ 141.26, 140.86, 128.33, 128.27, 128.22,
128.17, 128.14, 128.08, 126.85, 126.75, 62.76, 62.37, 52.11, 51.54,
31.65, 19.78, 14.08 ppm; HRMS (ESI) calcd for C25H31N2 (M + H+)
359.2487, found 359.2490; IR (KBr) δ 3288, 3022, 2956, 2899, 2824,
1519, 1485, 1227, 903 cm−1.
127.2, 61.0, 60.0, 58.8, 57.8, 53.6, 52.5, 52.4, 52.3, 33.3, 32.4, 23.3,
23.0, 20.5, 20.0, 15.0, 14.8, 11.8, 10.6 ppm; HRMS (ESI) calcd for
C21H30N2 (M + H+) 311.2487, found 311.2484; IR (KBr) 3325, 3004,
2896, 1512 cm−1.
(1S,2R)-N1,N2-Dibenzyl-N1-methyl-1-phenylpropane-1,2-dia-
mine 2j. Yellowish oil: 1H NMR (300 MHz, CDCl3) δ 7.37−7.11 (m,
15H), 4.10 (d, J = 13.2 Hz, 1H), 3.78 (d, J = 13.2 Hz, 1H), 3.60 (d, J =
10.5 Hz, 1H), 3.47−3.23 (m, 3H), 1.87 (s, 3H), 0.94 (d, J = 6.1 Hz,
3H); 13C NMR (75 MHz, CDCl3) δ 139.2, 139.2, 134.3, 129.7, 128.7,
128.6, 128.4, 128.0, 127.6, 127.4, 127.0, 73.0, 58.4, 51.0, 36.5, 29.7,
17.0 ppm; HRMS (ESI) calcd for C24H29N2 (M + H+) 345.2331,
found 345.2339; IR (KBr) δ 3351, 3004, 2982, 2929, 2872, 1678,
1492, 1439, 1357, 1113, 1021, 870 cm−1.
N1,N2-Dibenzyl-1-phenylhexane-1,2-diamine 2c. Yellowish
1
oil: H NMR (500 MHz, CDCl3) δ 7.60−7.15 (m, 15H), 3.88 (d, J
= 4.2 Hz, 1H), 3.78 (d, J = 13.4 Hz, 1H), 3.73 (s, 2H), 3.48 (d, J =
13.4 Hz, 1H), 2.73 (dt, J = 8.2, 4.2 Hz, 1H), 2.12 (s, 2H), 1.40−1.25
(m, 2H), 1.25−1.05 (m, 4H), 0.80 (t, J = 7.1 Hz, 3H); 13C NMR (75
MHz, CDCl3) δ 141.23, 140.81, 128.35, 128.29, 128.26, 128.20,
128.17, 128.11, 126.88, 126.79, 62.74, 62.51, 52.11, 51.53, 29.06,
28.79, 22.72, 13.97 ppm; HRMS (ESI) calcd for C26H33N2 (M + H+)
373.2644, found 373.2646; IR (KBr) δ 3294, 3028, 2948, 2916, 2866,
1507, 1489, 1206, 791 cm−1.
(1R,2S)-1-Phenyl-N1,N2-bis((S)-1-phenylethyl)propane-1,2-
1
diamine 2k. Pale yellow oil: α21 −136.2 (c 0.9, CHCl3); H NMR
D
(300 MHz, CDCl3) δ 7.44−7.12 (m, 15H), 3.64−3.60 (m, 2H), 3.35
(q, J = 6.4 Hz, 1H), 2.55 (dq, J = 3.7, 6.7 Hz, 1H), 1.89 (br s, 2H),
1.48 (d, J = 6.7 Hz, 3H), 1.26 (d, J = 6.5 Hz, 3H), 0.83 (d, J = 6.6 Hz,
3H); 13C NMR (75 MHz, CDCl3) δ 146.0, 145.8, 142.4, 128.3, 128.2,
128.1, 127.5, 127.0, 126.9, 126.7, 126.4, 60.0, 55.2, 55.0, 54.5, 24.7,
24.5, 15.6 ppm; HRMS (ESI) calcd for C25H30FN2 (M + H+)
377.2393, found 377.2390; IR (KBr) 3291, 3062, 3023, 2962, 2923,
2861, 1491, 1451, 1120 cm−1.
N1,N2-Dibenzyl-1-(4-fluorophenyl)propane-1,2-diamine 2d.
1
Yellowish oil: H NMR (500 MHz, CDCl3) δ 7.45−7.22 (m, 12H),
7.07 (t, J = 8.7 Hz, 2H), 3.85−3.70 (m, 4H), 3.47 (d, J = 13.4 Hz, 1H),
2.91 (dq, J = 6.5, 4.5 Hz, 1H), 1.98 (br s, 2H), 1.00 (d, J = 6.5 Hz,
3H); 13C NMR (125 MHz, CDCl3) δ 162.0 (d, J = 238.8 Hz), 140.7,
140.6, 136.9 (d, J = 3.0 Hz), 129.6 (d, J = 7.5 Hz), 128.5, 128.4, 128.2,
128.0, 127.0, 126.9, 115.0 (d, J = 20.3 Hz), 63.5, 57.3, 52.9, 51.6, 15.8
ppm; HRMS (ESI) calcd for C23H26FN2 (M + H+) 349.2080, found
349.2084; IR (KBr) δ 3295, 3026, 2962, 2922, 2827, 1602, 1506, 1452,
1219, 832 cm−1.
(1R,2S)-1-(4-Fluorophenyl)-N1,N2-bis((S)-1-phenylethyl)-
propane-1,2-diamine 2l. Yellowish oil: α21 −60.6 (c 0.7, CHCl3);
D
1H NMR (300 MHz, CDCl3) δ 7.39−7.17 (m, 8H), 7.06−6.92 (m,
6H), 3.50 (m, 2H), 3.25 (q, J = 6.6 Hz,1H), 2.44 (dq, J = 3.8, 6.3 Hz,
1H), 1.93 (br s, 2H), 1.41 (d, J = 6.7 Hz, 3H), 1.21 (d, J = 6.6 Hz,
3H), 0.75 (d, J = 6.6 Hz, 3H); 13C NMR (75 MHz, cdcl3) δ 161.6 (d, J
= 244.0 Hz), 145.8, 137.8 (d, J = 3.0 Hz), 128.9 (d, J = 7.8 Hz), 128.3,
128.2, 126.9, 126.8, 126.7, 126.3, 114.8 (d, J = 21.1 Hz), 59.1, 55.1,
54.9, 54.4, 24.6, 24.3, 15.5 ppm; HRMS (ESI) calcd for C25H30FN2 (M
+ H+) 377.2393, found 377.2390; IR (KBr) δ 3441, 3303, 2970, 2931,
2860, 1680, 1609, 1507, 1450, 1365, 1262, 1223, 1127, 823 cm−1.
(1R,2S)-1-(4-Fluorophenyl)-N1,N2-bis((S)-1-phenylethyl)-
butane-1,2-diamine 2m. Yellowish oil: α20D −88.5° (c 1.0, CHCl3);
1H NMR (300 MHz, CDCl3) δ 7.40−6.94 (m, 14H), 3.62 (d, J = 3.5
N1,N2-Dibenzyl-1-(p-tolyl)propane-1,2-diamine 2e. Yellowish
1
oil: H NMR (300 MHz, CDCl3) δ 7.37−7.18 (m, 14H), 3.82−3.68
(m, 4H), 3.49 (d, J = 13.4 Hz, 1H), 2.91 (dq, J = 6.5, 4.5 Hz, 1H), 2.39
(s, 3H), 1.87 (br s, 2H), 1.01 (d, J = 6.5 Hz, 3H); 13C NMR (75 MHz,
CDCl3) δ 141.0, 140.7, 138.2, 136.5, 129.0, 128.3, 128.2, 128.0, 126.8,
126.7, 64.3, 57.4, 51.5, 21.0, 15.7 ppm; HRMS (ESI) calcd for
C24H29N2 (M + H+) 345.2331, found 345.2333; IR (KBr) δ 3291,
3023, 2957, 2921, 2849, 1492, 1452, 1111, 1026, 820 cm−1.
N1,N2-Dibenzyl-1-(4-fluorophenyl)butane-1,2-diamine 2f.
1
Yellowish oil: H NMR (300 MHz, CDCl3) δ 7.45−7.22 (m, 12H),
Hz, 1H), 3.52 (q, J = 6.8 Hz, 1H), 3.24 (q, J = 6.6 Hz, 1H), 3.03 (br s,
2H), 2.17 (m, 1H), 1.45 (d, J = 6.7 Hz, 3H), 1.39−1.28 (m, 1H), 1.26
(d, J = 6.6 Hz, 3H), 0.96−0.86 (m, 1H), 0.64 (t, J = 7.4 Hz, 3H); 13C
NMR (75 MHz, CDCl3) δ 161.5 (d, J = 249.0 Hz), 145.8, 145.6,
137.7, 129.1, 128.3, 126.8, 126.7, 114.9 (d, J = 28.5 Hz), 61.4, 58.7,
55.0, 54.4, 24.7, 24.2, 21.3, 11.1 ppm; HRMS (ESI) calcd for
C26H32FN2 (M + H+) 391.2550, found 391.2543; IR (KBr) δ 3437,
3309, 2991, 2941, 2891, 1671, 1600, 1503, 1430, 1349, 1251, 1111,
833 cm−1.
Experimental Procedure for the Preparation of Cyclic Ureas.
To a stirred mixture of diamine (70 mg, 0.212 mmol) and sodium
carbonate (0.318 mmol, 34 mg) in THF (0.6 mL, freshly distilled) was
added a solution of triphosgene (0.255 mmol, 76.3 mg) in THF (0.6
mL) dropwise at rt. After stirring at this temperature overnight, water
and ethyl acetate were added. The aqueous layer was extracted with
ethyl acetate (3 × 10 mL), and the collected organic layers were
washed with brine, dried over Na2SO4 and concentrated to obtain a
red wine crude oil, which was purified by passing it through a silica-gel
chromatography column with 9:1 (hexane:ethyl acetate) as eluent to
obtain a colorless oil.
7.07 (t, J = 6.0 Hz, 2H), 3.87 (d, J = 4.2 Hz, 1H), 3.81−3.72 (m, 3H),
3.47 (d, J = 13.4 Hz, 1H), 2.66 (m, 1H), 1.84 (s, 2H), 1.41 (m, 2H),
0.86 (t, J = 7.4 Hz, 3H); 13C NMR (75 MHz, CDCl3) δ 161.9 (d, J =
252.8 Hz), 140.8, 140.7, 136.9 (d, J = 3.0 Hz), 129.5 (d, J = 7.5 Hz),
128.4, 128.3, 128.2, 128.1, 126.9, 126.8, 115.0 (d, J = 20.3 Hz), 64.3,
62.0, 52.1, 51.4, 22.0, 11.0 ppm; HRMS (ESI) calcd for C24H28FN2 (M
+ H+) 363.2237, found 363.2241; IR (KBr) 3291, 3060, 3023, 2922,
2852, 1601, 1507, 1452, 1217, 1117, 830 cm−1.
N2,N3-Dibenzyl-5-methylhexane-2,3-diamine 2g. Yellowish
1
oil: H NMR (300 MHz, CDCl3) δ 7.35−7.21 (m, 10H), 3.84−3.61
(m, 4H), 2.91−2.46 (m, 4H), 1.71−1.54 (m, 1H), 1.44−1.12 (m, 2H),
1.07 (d, J = 6.6 Hz, 3H), 0.89 (d, J = 6.5 Hz, 3H), 0.85 (d, J = 6.5 Hz,
3H); 13C NMR (75 MHz, CDCl3) δ 140.0, 140.3, 128.5, 128.2, 128.4,
127.0, 126.9, 58.3 (minor), 57.3 (major), 54.8 (minor), 52.3 (major),
51.7 (major), 51.3 (minor), 51.2 (minor), 51.1 (major), 40.2 (minor),
38.9 (major), 25.3 (minor), 25.0 (major), 23.7 (minor), 23.11
(major), 22.6 (major), 22.3 (minor), 16.2 (minor), 15.2 (major) ppm;
HRMS (ESI) calcd for C21H31N2 (M + H+) 311.2487, found
311.2492; IR (KBr) δ 3291, 3025, 2955, 1453 cm−1.
N2,N3-Dibenzylhexane-2,3-diamine 2h. Yellowish oil: 1H NMR
(300 MHz, CDCl3) δ 7.38−7.22 (m, 10H), 3.89 (d, J = 13.2 Hz, 1H),
3.78 (d, J = 13.0 Hz, 1H), 3.68 (d, J = 12.7 Hz, 1H), 3.66 (d, J = 13.1
Hz, 1H), 2.63 (dq, J = 6.5, 6.7 Hz, 1H), 2.43 (m, 1H), 2.09 (br s, 1H),
1.36 (m, 4H), 1.09 (d, J = 6.3 Hz, 3H), 0.92 (t, J = 7.2 Hz, 3H); 13C
NMR (125 MHz, CDCl3) δ 140.1, 140.0, 128.1, 127.0, 61.2, 54.8, 51.4,
32.3, 18.8, 16.9, 14.1 ppm; HRMS (ESI) calcd for C20H29N2 (M + H+)
297.2331, found 297.2329; IR (KBr) δ 3433, 3291, 3024, 2955, 2863,
1667, 1451 cm−1.
(4R,5S)-1,3-Dibenzyl-4-methyl-5-phenylimidazolidin-2-one
1
3. White solid, mp 65 −70 °C (yield 45 mg, 59%): H NMR (300
MHz, tol-d8) δ 7.34−6.93 (m, 15 H), 5.32 (d, J = 14.8 Hz, 1H), 5.02
(d, J = 15.1 Hz, 1H), 4.06 (d, J = 8.8 Hz, 1H), 3.94 (d, J = 15.2 Hz,
1H), 3.58 (d, J = 14.8 Hz, 1H), 3.33 (dq, J = 8.5, 6.5 Hz, 1H), 0.48 (d,
J = 6.5 Hz, 3H); 13C NMR (75 MHz, CDCl3) δ 161.2, 137.5, 137.2,
135.7, 128.5, 128.4, 128.2, 128.0, 127.3, 127.2, 60.9, 52.7, 45.6, 14.8
ppm; HRMS calcd for C24H25N2O (M + H+) 357.1967, found
357.1963; IR (KBr) d 3037, 2984, 2931, 1691, 1439, 1358, 1078, 1028
cm−1.
N3,N4-Dibenzylheptane-3,4-diamine 2i. Yellowish oil: 1H NMR
(300 MHz, CDCl3) δ 7.42−7.24 (m, 8H), 7.12−7.03 (m, 2H), 3.82−
3.61 (m, 4H), 2.66−2.45 (m, 2H), 1.77−1.21 (m, 8H), 0.89 (m, 6H);
13C NMR (300 MHz, CDCl3) δ 141.7, 141.6, 128.8, 128.7, 128.6,
(4R,5S)-1,3-Dibenzyl-4-ethyl-5-(4-fluorophenyl)-
imidazolidin-2-one 4. White solid, mp 69 −74 °C (yield 66 mg,
1
80%): H NMR (500 MHz, tol-d8) δ 7.25 (d, J = 7.6 Hz, 2H), 7.14−
E
dx.doi.org/10.1021/jo400501k | J. Org. Chem. XXXX, XXX, XXX−XXX