Helvetica Chimica Acta Vol. 86 (2003)
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(m, 1H); 6.26 6.41( m, 1H); 7.28 7.41( m, 1 H). 13C-NMR (100 MHz, CDCl3): 20.8; 36.9; 103.5; 109.3; 138.6;
156.5. Combustion analysis of this compound was carried out with its N-benzoyl derivative.
(S)-1-(Furan-2-yl)-2-phenylethanamine ((S)-4e). B.p: 140 1508/0.1Torr (bulb-to-bulb distillation) ([21]:
20
167 1688/0.4 Torr). a À18.8 (c 0.1, EtOH). 1H-NMR (400 MHz, CDCl3): 2.14 (s, 2 H); 2.73 3.28
D
(m, 2 H); 4.03 4.31( m, 1H); 6.03 6.13 ( m, 1H); 6.25 6.36 ( m, 1H); 7.05 7.46 ( m, 6 H).
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D
(S)-(Furan-2-yl)(phenyl)methanamine ((S)-4f). B.p: 125 1358/12 Torr (bulb-to-bulb distillation). a
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À23.2 (c 1, CHCl3) ([5b][19]: a 18.3 (c 1, EtOH) for (R)-enantiomer). 1H-NMR (400 MHz, CDCl3):
D
1.85 (s, 2 H); 5.11 (br. s, 1H); 6.01 6.13 ( m, 1H); 6.20 6.33 ( m, 1H); 7.16 7.49 ( m, 6 H).
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(R)-(Furan-2-yl)(phenyl)methanamine ((R)-4f). Yield 91%. a 22.1( c 1, CHCl3).
D
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(S)-(3,4-Dimethoxyphenyl)(furan-2-yl)methanamine ((S)-4g). a 8.6 (c 0.5, CHCl3). IR: 3380,
D
3105, 3000, 2820, 1590, 1510, 1460. 1H-NMR (400 MHz, CDCl3): 2.03 (s, 2 H); 3.83 (s, 6 H); 5.08 (s, 1H); 6.02
6.13 (m, 1H); 6.21 6.36 ( m, 1H); 6.71 7.0 ( m, 4 H). 13C-NMR (100 MHz, CDCl3): 56.3; 56.5; 58.8; 104.3;
110.2; 113.8; 114.9; 120.6; 135.8; 140.5; 145.7; 147.3; 157.7. Anal. calc. for C13H15NO3: C 66.94, H 6.48, N 6.00;
found: C 66.88, H 6.33, N 5.83.
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D
(R)-(3,4-Dimethoxyphenyl)(furan-2-yl)methanamine ((R)-4g). a À9.3 (c 0.5, CHCl3).
General Procedure for N-Protection. The amine (2.5 mmol; 4a 4g) was dissolved in 5 ml of pyridine, and to
this soln. was added PhCOCl (0.35 ml) dropwise at 08. The mixture was stirred at r.t. for 2 h, then 6n HCl (4 ml),
H2O (4 ml), and Et2O (20 ml) were added. The org. layer was separated, and washed with brine and dried
(Na2SO4). Crude product was purified by crystallization or CC.
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D
(S)-N-[1-(Furan-2-yl)ethyl]benzamide ((S)-5a). Yield 93%. a À51.6 (c 1, CHCl3). IR (KBr): 3450,
3090, 2910, 1660, 1510, 1480. 1H-NMR (400 MHz, CDCl3): 1.50 (d, J 7.1, 3 H); 5.30 5.33 (q, J 7.1, 1 H); 6.14
(d, J 2.9, 1H); 6.23 (br. s, 1H); 6.41( d, J 7.0, 1H); 7.25 7.75 ( m, 6 H). 13C-NMR (100 MHz, CDCl3): 20.1;
43.7; 106.2; 110.6; 127.4; 128.9; 131.9; 134.8; 142.3; 155.8; 166.9. Anal. calc. for C13H13NO2: C 72.54, H 6.09, N
6.51; found: C 72.71, H 6.24, N 6.32.
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D
(R)-N-[1-(Furan-2-yl)ethyl]benzamide ((R)-5a). Yield 88%. M.p: 109 1118. a 52 (c 1, CHCl3).
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D
(S)-N-[1-(Furan-2-yl)-propyl]benzamide ((S)-5b). Yield 91%. M.p: 52 538. a 84.3 (c 1, CHCl3).
1H-NMR (400 MHz, CDCl3): 0.96 (t, J 7.1, 3 H); 1.78 2.13 (m, 2 H); 5.11 5.38 (m, 1H); 6.16 6.36 ( m, 2 H);
6.42 6.71(br. s, 1H); 7.28 7.58, 7.70 7.86 ( m, 6 H). Anal. calc. for C14H15NO2: C 73.34, H 6.59, N 6.11; found C
73.56, H 6.71, N 6.23.
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D
(R)-N-[1-(Furan-2-yl)propyl]benzamide ((R)-5b). Yield 87%. a À81.2 (c 1, CHCl3).
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D
(R)-N-[1-(Furan-2-yl)-2-methylpropyl]benzamide ((R)-5c). Yield 92%. M.p. 79 808. a 81.8 (c 1,
CHCl3). 1H-NMR (400 MHz, CDCl3): 0.85 (d, J 6.7, 3 H); 0.95 (d, J 6.7, 3 H); 2.10 (sept., J 6.9, 1H); 5.10
(t, J 7.7, 1H); 6.11 ( d, J 2.5, 1H); 6.21 ( t, J 2.8, 1H); 6.40 ( d, J 8.0, 1H); 7.10 ( s, 1H); 7.18 7.71
(m, 5 H). 13C-NMR (100 MHz, CDCl3): 19.2; 19.6; 32.8; 53.6; 107.3; 110.5; 127.4; 128.9; 131.9; 134.9; 142.1;
153.9; 167.2. Anal. calc. for C15H17NO2: C 74.05, H 7.04, N 5.76; found: C 74.23, H 6.92, N 5.51.
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D
(R)-N-[1-(Furan-2-yl)-2,2-dimethylpropyl]benzamide ((R)-5d). Yield 86%. M.p. 108 1098. a 5.2
(c 1, CHCl3). 1H-NMR (400 MHz, CDCl3): 1.00 (s, 9 H); 5.11 (d, J 9.8, 1H); 6.13 ( d, J 2.9, 1H); 6.23
(dd, J 1.8, 2.8, 1 H); 6.59 (d, J 9.1, 1 H); 7.21 (s, 1H); 7.22 7.60 ( m, 5 H). 13C-NMR (100 MHz, CDCl3): 27.1;
36.4; 56.3; 108.7; 110.6; 127.8; 129.9; 130.5; 135.2; 141.8; 153.5; 172.2. MS: 257 (M ), 242, 202, 200, 121, 106, 105
(100), 77, 69, 57, 51. Anal. calc. for C16H19NO2: C 74.68, H 7.44, N 5.44; found: C 74.61, H 7.32, N 5.26.
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D
(S)-N-[1-(Furan-2-yl)-2-phenylethyl]benzamide ((S)-5e). Yield 88%. M.p. 112 1138. a À4.7 (c 0.4,
CHCl3). 1H-NMR (400 MHz, CDCl3): 3.16 3.25 (m, 2 H) ; 5.28 5.68 (m, 1H); 6.01 6.13 ( m, 1H); 6.18 6.30
(m, 1H); 6.38 6.61( m, 1H); 6.96 7.83 ( m, 1 1 H)1.3C-NMR (100 MHz, CDCl3): 41.2; 53.8; 104.2; 101.7; 125.7;
127.4; 128.6; 158.7; 130.7; 133.8; 137.7; 140.1; 154.4; 167.8. Anal. calc. for C19H17NO2: C 78.33, H 5.88, N 4.81;
found: C 78.51, H 5.78, N 4.98.
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D
(S)-N-[(Furan-2-yl)(phenyl)-methyl]benzamide ((S)-5f). Yield 87%. M.p. 136 1378. a À32.7 (c
0.8, CHCl3). IR: 3450, 2910, 3090, 1660, 1510, 1480. 1H-NMR (400 MHz, CDCl3): 6.21 6.23 ( m, 1H); 6.3 6.4
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(m, 1H); 6.5 ( d, J 9, 1H); 6.83 7.15 (br. s, 1H); 7.08 7.58 ( m, 1 1 H). C-NMR (100 MHz, CDCl3): 55.1;
103.8; 109.4; 126.2; 127.2; 128.6; 131.5; 133.4; 136.6; 139.8; 156.8; 167.6. MS: 277 (M ), 248, 172, 157, 156, 144,
128, 105 (100), 77, 51. Anal. calc. for C18H15NO2: C 77.96, H 5.45, N 5.05; found: C 78.12, H 5.67, N 5.37.
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D
(S)-N-[(3,4-Dimethoxyphenyl)(furan-2-yl)methyl]benzamide ((S)-5g). Yield 87%. M.p. 150 1528. a
À3.8 (c 0.1, CHCl3). 1H-NMR (400 MHz, CDCl3): 3.77 (s, 3 H); 3.79 (s, 3 H); 6.21( d, J 3.2, 1H); 6.32
(dd, J 1.9, 3.2, 1 H); 6.42 (d, J 8.1, 1 H); 6.70 6.81 (m, 4 H); 7.31(br. s, 1H); 7.40 7.72 ( m, 5 H). 13C-NMR
(100 MHz, CDCl3): 51.8; 56.3; 108.3; 110.8; 111.2; 111.6; 119.6; 127.5; 129.1; 132.2; 132.6; 134.5; 142.9; 149.1;
149.5; 153.9; 166.8. MS: 337 (100, M ), 308, 232, 217, 216, 204, 201, 188, 173, 164, 105, 94, 77, 51. Anal. calc. for
C20H19NO4: C 71.20, H 5.68, N 4.15; found: C 71.36, H 5.81, N 4.36.