H. S. Knowles et al. / Tetrahedron 56 (2000) 979–988
985
Found: Mϩ, 323.1524. C20H21NO3 requires for Mϩ,
323.1521. The presence of the minor diastereoisomer was
indicated by: dH (500 MHz; CDCl3) 4.66 (1H, d, J16 Hz,
PhCHN), 4.18–4.16 (1H, m, NCHCO), 3.81 (1H, d,
J16 Hz, PhCHN), 3.70 (3H, s, CO2CH3), 3.15–3.13 (1H,
m, PhCH2CH), 2.89–2.81 (1H, m, PhCH), 2.74 (1H, dd,
J11 and 3 Hz, PhCH); dC (67.5 MHz; CDCl3) 170.1,
169.0 (CO2CH3, NCO), 143.2, 142.9 (CyCH), 58.5
(NCHCO), 52.5 (CO2CH3), 48.7 (PhCH2N), 39.5
(CHCH2CH or PhCH2CH), 34.1 (PhCH2CH), 29.7
(CHCH2CH or PhCH2CH).
137.6 (CyCH), 58.0 (NCHCO), 52.9 (CO2CH3), 43.9
(PhCH2CH), 36.4, 27.8 (PhCH2CH and CHCH2CH).
2-(N-Benzenesulfonylamino)-2-methoxycarbonylethyl (E)-
3-phenylpropenoate 10. Rf 0.2 (silica; petroleum ether–
ethyl acetate, 5:2); nmax (thin film) 3320 (s), 1738 (s),
1716 (s), 1639 (m), 1642 (m) cmϪ1; dH (270 MHz;
CDCl3) 7.90–7.49 (10H, m, aromatics), 7.74 (1H, d,
J16 Hz, PhCHyCH), 6.42 (1H, d, J16 Hz, PhCHyCH),
5.64 (1H, d, J8.5 Hz, NH), 4.44–4.39 (1H, m, NCHCO),
3.74 (1H, dd, J10.5 and 3.5 Hz, CHOCO), 3.59 (1H, dd,
J10.5 and 4 Hz, CHOCO), 3.64 (3H, s, CO2CH3); dC
(67.5 MHz; CDCl3) 169.7, 166.6 (CO2CH3 and OCOCH),
146.5 (PhCHyCH), 140.2, 134.4 (CHyC), 131.1, 129.6,
129.3, 128.7, 127.5 (CHyC), 117.1 (PhCHyCH), 64.9
(CH2O), 55.4 (NCHCO), 53.5 (CO2CH3); m/z (CI, NH3)
407 (MϩNHϩ4 , 6%), 390 (MϩHϩ, 3), 259 (85), 242 (60),
177 (10), 166 (12), 148 (35), 102 (100); Found: MϩNHϩ4 ,
407.1279. C19H19NO6S requires for MϩNHϩ4 , 407.1277.
2-(N-Benzylamino)-2-methoxycarbonylethyl (E)-3-phenyl-
propenoate 5. Rf 0.8 (silica; ethyl acetate); nmax (thin film)
1738 (s), 1716 (s), 1637 (m) cmϪ1; dH (270 MHz; CDCl3)
7.72–7.68 (1H, d, J15 Hz, PhCHyCH), 7.45–7.10 (10H,
m, aromatics), 6.32 (1H, d, J15 Hz, PhCHyCH), 4.49–
4.25 (2H, m, CH2O), 3.83 (3H, s, CO2CH3), 3.79–3.61 (2H,
m, PhCH2), 3.55 (1H, t, J6 Hz, NCHCO); dC (67.5 MHz;
CDCl3) 168.7, 167.6 (CO2CH3, NCO), 145.3 (PhCHyCH),
136.4, 134.9 (CyCH), 130.3, 130.0, 129.1, 128.9, 128.7,
128.4, 127.7 (CHyC), 117.0 (PhCHyCH), 62.3 (CH2O),
53.1 (PhCH2), 52.1 (CO2CH3); m/z (CI, NH3) 340
(MϩHϩ, 100%), 192 (10), 131 (10), 91 (10); Found:
MϩHϩ, 323.1554. C20H22NO4 requires for MϩHϩ,
340.1549.
General procedure for acylation of N-sulfonylamines to
give 11a–d and 17–20
To a stirred solution of the amine (0.68–2.34 mmol) in
dry tetrahydrofuran (10–20 cm3) at 0ЊC under a nitrogen
atmosphere was added sodium hydride (0.82–2.84 mmol)
and the reaction was allowed to stir for 1 h. A solution of
the acid chloride (0.82–2.84 mmol) in tetrahydrofuran
(1–2 cm3) was then added and the reaction was allowed to
warm to rt and stirred overnight. The solvent was removed
in vacuo and the residue dissolved in ethyl acetate, washed
with water, dried (MgSO4) and evaporated in vacuo to
afford crude product, purified by column chromatography
(silica) to afford the amide (63–99%).
Methyl (E)-3-chloro-2-cinnamamidopropanoate 8. White
solid; mp 145–146ЊC; Rf 0.5 (silica; diethyl ether); nmax
(thin film) 3233 (s), 1742 (s), 1652 (s), 1618 (s), 1525 (s),
1441 (w), 1358 (m), 1211 (s) cmϪ1; dH (270 MHz; CDCl3)
7.77 (1H, d, J16 Hz, PhCHCH), 7.63–7.36 (5H, m,
aromatics), 6.76 (1H, d, J7 Hz, NH), 6.63 (1H, d,
J16 Hz, PhCHyCH), 5.25–5.23 (1H, m, NCHCO), 4.15
(1H, dd, J11.5 and 3 Hz, CHCl), 4.07 (1H, dd, J11.5 and
3.5 Hz, CHCl), 3.93 (3H, s, CO2CH3); dC (67.5 MHz;
CDCl3) 171.4, 169.4 (CO2CH3 and NCO), 142.5
(PhCHyCH), 130.0, 128.9, 128.0 (aromatics), 119.5
(PhCHyCH), 52.3 (CO2CH3), 53.1 (NCHCO), 45.2
(CH2Cl); m/z (CI, NH3) 270 (37MϩHϩ, 15%), 234 (55),
232 (100); Found: 35MϩHϩ, 268.0738. C13H14ClNO3S
requires for 35MϩHϩ, 268.0740.
N-Benzoyl-N-benzylbenzenesulfonamide 11a. White solid;
mp 78–79ЊC; Rf 0.3 (petroleum ether–ethyl acetate, 3:1);
nmax (thin film) 1688 (s), 1448 (s), 1358 (s), 1324 (m), 1170
(s), 1087 (m) cmϪ1; dH (270 MHz; CDCl3) 7.73–7.18 (15H,
m, aromatics), 4.91 (2H, s, PhCH2); dC (67.5 MHz; CDCl3)
171.5 (NCO), 138.8, 136.0, 134.8 (CyCH), 133.6, 131.8,
128.7, 128.5, 128.4, 128.2, 127.9, 127.8 (CHyC), 51.3
(PhCH2); m/z (CI, NH3) 369 (MϩNHϩ4 , 15%), 352
(MϩHϩ, 45), 212 (100); Found: MϩHϩ, 352.1013.
C20H17NO3S requires for MϩHϩ, 352.1007.
N-Benzenesulfonyl-4-benzylpyroglutamate 9. Rf 0.5 (silica;
petroleum ether–diethyl ether, 2:5); nmax (thin film) 1743
(s), 1447 (s), 1361 (m), 1210 (w), 1167 (s), 1140 (m), 1083
(w) cmϪ1; dH (270 MHz; CDCl3) (major diastereoisomer)
8.33–7.21 (10H, m, aromatics), 4.96 (1H, dd, J6 and 4 Hz,
NCHCO), 3.91 (3H, s, CO2CH3), 3.34 (1H, dd, J14 and
4.5 Hz, PhCH), 3.05 (1H, dd, J10 and 4.5 Hz, PhCH2CH),
2.79 (1H, dd, J14 and 9 Hz, PhCH), 2.35–2.30 (2H, m,
CHCH2CH); dC (67.5 MHz; CDCl3) (major diastereo-
isomer) 173.7, 170.9 (CO2CH3 and NCO), 137.7 (CyCH),
134.3, 129.1, 128.8, 128.7, 128.6, 126.8 (CHyC), 57.4
(NCHCO), 52.8 (CO2CH3), 43.0 (PhCH2CH), 35.8, 29.7
(PhCH2CH and CHCH2CH); m/z (CI, NH3) 391
(MϩNHϩ4 , 100%), 374 (MϩHϩ, 71), 314 (8), 310 (10),
234 (41), 232 (35), 172 (10); Found: MϩHϩ, 374.1050.
C19H19NO5S requires for MϩHϩ, 374.1062. The presence
of the minor diastereoisomer was indicated by: dH
(270 MHz; CDCl3) 4.92–4.89 (1H, m, NCHCO), 3.99
(3H, s, CO2CH3), 2.62 (1H, dd, J12 and 9 Hz, PhCH);
dC (67.5 MHz; CDCl3) 174.1, 171.5 (CO2CH3 and NCO),
N-Benzyl-N-(2,2-dimethylpropionyl)benzenesulfonamide
11b. White solid; mp 100–102ЊC; Rf 0.4 (petroleum ether–
ethyl acetate, 2:1); nmax (thin film) 2925 (m), 2936 (m),
1686 (s), 1447 (m), 1148 (m), 1350 (s), 1310 (w), 1169
(s), 1088 (m), 971 (w), 739 (w) cmϪ1; dH (270 MHz;
CDCl3) 7.81–7.21 (10H, m, aromatics), 5.02 (2H, s,
NCH2), 1.25 (9H, s, CMe3); dC (67.5 MHz; CDCl3) 181.8
(NCO), 139.0, 136.0 (CyCH), 133.2, 128.4, 127.7, 127.4
(CHyC), 51.0 (PhCH2), 42.6 (CMe3), 27.9 (CMe3); m/z (CI,
NH3) 349 (MϩNHϩ4 , 17%), 332 (MϩHϩ, 78), 265 (30), 248
(17), 192 (100); Found: MϩHϩ, 332.1315. C18H21NO3S
requires for MϩHϩ, 332.1313.
N-Benzyl-N-ethanoylbenzenesulfonamide 11c. White solid;
mp 72–75ЊC; Rf 0.3 (petroleum ether–diethyl ether, 2:3);
nmax (thin film) 1705 (s), 1448 (m), 1354 (s), 1236 (s), 1168
(m), 1090 (m) cmϪ1; dH (270 MHz; CDCl3) 7.89–7.16