W. Buijs et al. / Journal of Organometallic Chemistry 641 (2002) 71–80
77
3.3. Syntheses of the copper(II) compounds
solution was shaken with 50 ml 1 M HCl, then with 50
ml of NaHCO3 solution. The solvent of the organic
phase was evaporated; to crystallize the oily residue 5
ml Et2O and alkane (40:60) were added. The white
precipitate was collected on a filter, washed with Et2O,
and dried in vacuo. Yield: 11.58 g (78.67%). Anal. Calc.
for C13H17NO4 (251.28): C, 62.14; H, 6.82; N, 5.57.
Found: C, 61.91; H, 6.77; N, 5.54%. 1H-NMR (300
MHz, d6-acetone): l=1.55 (s, 2CH3, 6H); 3.67 (s,
COOꢀCH3, 3H); 4.03 (s, OCH3, 3H); 7.06 (t, ArH5, 1H,
J=8 Hz); 7.16 (d, ArH3, 1H, J=8 Hz); 7.50 (t, ArH4,
1H, J=8 Hz); 8.04 (d, ArH6, 1H, J=8 Hz). 13C-NMR
(300 MHz, d3-CHCl3): l=24.74 (2CH3); 52.31
(COOCH3); 55.76 (OCH3); 56.33 (NC); (111.15; 121.05;
121.25; 131.93; 132.65; 157.36) (CAromat); 163.88
(COOCH3); 175.08 (CO).
3.3.1. [Cu2(v2-O2CꢀC(CH3)2ꢀNHꢀCOꢀC6H5)4]
(Cu2HL14)
To 6.5 g (31.37 mmol) C6H5ꢀCOꢀNHꢀC(CH3)2ꢀ
COOH, dissolved 600 ml H2O–iso-propanol (5:7), was
added 1.66 g (7.51 mmol) [(CuCO3)(Cu(OH)2)]. The
mixture was heated for 24 h at a temperature of 70 °C.
After 24 h, the turquoise green precipitate was collected
on a filter, washed with Et2O and dried in vacuo. Yield:
3.3
g
(91.7%). Anal. Calc. for [Cu2(m2-O2CꢀC-
(CH3)2ꢀNHꢀCOꢀC6H5)4] (C44H48Cu2N4O12) (951.98):
C, 55.51; H, 5.08; N, 5.89. Found: C, 55.78; H, 5.17; N,
5.87%. IR (KBr, cm−1): w(NꢀH) 3396 (s), w(CꢀH,
aromate) 3062 and 3030 (w), w(CꢀH, methyl groups)
2984 and 2936 (s), w(CꢁO, amide I) 1620 (s), w(CꢁC)
1620 (m), wasym.(CꢁO, COO−) 1578 (s), l (NꢀH, amide
II) 1514 (s), wsym.(CꢁO, COO−) 1414 (s), l (C−H,
monosubstitution of the aromate) 714 and 692.
3.2.8. 2-(2-Hydroxybenzoyl)-amino-2-methylpropionic
acid (H3L9)
To 10.8 g (42.98 mmol) N-2-methoxybenzoyl-a-
aminoisobutyric acid methylester, dissolved in 70 ml
MeOH (ice bath), were added 77 ml aqueous 1 M
NaOH solution. After 24 h, 150 ml 1 M HCl were
added. The white precipitate was collected on a filter,
washed with water and dried in vacuo. Yield: 9.1 g
(89.22%). Anal. Calc. for C12H15NO4 (237.26): C, 60.75;
H, 6.37; N, 5.90. Found: C, 60.80; H, 6.32; N, 6.01%.
1H-NMR (300 MHz, d6-acetone): l=1.64 (s, 2CH3,
6H); 4.03 (s, ArOCH3, 3H); 7.06 (t, ArH5, 1H, J=8
Hz); 7.17 (d, ArH3, 1H, J=8 Hz); 7.50 (t, ArH4, 1H,
J=8 Hz); 8.07 (d, ArH6, 1H, J=8 Hz). 13C-NMR (300
MHz, d6-acetone): l=25.83 (2CH3); 57.23 (OCH3);
57.71 (NC); (113.48; 122.34; 123.43; 133.04; 134.38;
159.35) (CAromat); 165.32 (COOH); 176.74 (CO).
3.3.2. [Cu(v1-O2CꢀC(CH3)2ꢀNHꢀCOꢀC6H5)(Me3NO)2]
(CuL1(Me3NO)2)
To 0.10 g (0.11 mmol) [Cu2(m2-O2CꢀC(CH3)2ꢀNHꢀ
COꢀC6H5)4], dissolved in 20 ml MeCN, was added
0.1577 g (2.10 mmol) Me3NO. The mixture was kept in
the refrigerator to crystallize. Yield: 0.0796 g (90.00%).
Anal. Calc. for [Cu(m1-O2CꢀC(CH3)2ꢀNHꢀCOꢀC6H5)-
(Me3NO)2] (C17H31CuN3O5) (421.00): C, 48.50; H, 7.42;
N, 9.98. Found: C, 47.70; H, 7.05; N, 10.48%. IR (KBr,
cm−1): w(NꢀH) 3372 (s), w(CꢀH, aromate) 3052 (w),
w(CꢀH, methyl groups) 2968 (w), w(CꢁO, amide I) 1632
(s), w(CꢁC) 1600 (m), wasym.(CꢁO, COO−) 1552(s), l
(NꢀH, amide II) 1510 (s), wsym.(CꢁO, COO−) 1390 (s), l
(CꢀH, monosubstitution of the aromate) 762 and 694.
To 5 g (25.28 mmol) 2-(2-methoxybenzoyl)-amino-2-
methylpropionic acid (see above), dissolved in 500 ml
dry dichlormethane under an Ar atmosphere, were
added 12.67 g (50.56 mmol) BBr3 (as an 1 M CH2Cl2
solution) within 1 h at a temperature of −78 °C. After
3 h, the mixture was poured on ice and extracted three
times with 200 ml of a CHCl3–EtOAc mixture (8:2).
The organic phase was extracted with 100 ml of a
NaHCO3 solution, and to the water phase was added
200 ml of 5 M aqueous HCl. The resulting white
precipitate was collected on a filter, washed with ice
water and dried in vacuo. Yield: 2.86 g (60.85%). Anal.
Calc. for C11H13NO4 (223.23): C, 59.19; H, 5.87; N,
3.3.3. [Cu2(v2-O2CꢀCH2ꢀNHꢀCOꢀC6H5)4] (Cu2HL24)
To 3 g (16.74 mmol) C6H5ꢀCOꢀNHꢀCH2ꢀCOOH,
dissolved 100 ml H2O–iso-propanol (5:7), was added
0.85 g (3.84 mmol) [(CuCO3)(Cu(OH)2)]. The mixture
was heated for 48 h at a temperature of 67 °C. Then
the solution was filtrated and the filtrate was evapo-
rated to give a turquoise blue powder. To remove
unreacted hippuric acid the precipitate is redissolved in
acetone, filtered again and dried in vacuo. Yield: 2.5 g
(90.58%). Anal. Calc. for [Cu2(m2-O2CꢀCH2ꢀNHꢀCOꢀ
C6H5)4] (C36H32Cu2N4O12) (839.76): C, 51.49; H, 3.84;
N, 6.67. Found: C, 51.32; H, 3.97; N, 6.60%. IR (KBr,
cm−1): w(NꢀH) 3408 (s), w(CꢀH, aromate) 3056 and
3026 (w), w(CꢀH, methylene group) 2976 and 2936 (s),
w(CꢁO, amide I) 1620 (s), w(CꢁC) 1620 (m), wasym.(CꢁO,
COO−) 1578(s), l (NꢀH, amide II) 1542 (s), wsym.(CꢁO,
COO−) 1398 (s), l (CꢀH, monosubstitution of the
aromate) 736 and 692.
1
6.27. Found: C, 59.02; H, 5.82; N, 6.28%. H-NMR
(300 MHz, d6-acetone): l=1.62 (s, CH3, 6H); 6.87 (m,
ArH5, ArH3, 2H, J=8 Hz); 7.40 (t, ArH4, 1H, J=8
Hz); 7.82 (d, ArH6, 1H, J=8 Hz). 13C-NMR (300
MHz, d6-acetone): l=25.95 (2CH3); 57.71 (NC);
(116.14; 119.16; 119.87; 128.67; 135.52; 163.11)
(CAromat); 171.39 (COOH); 176.13 (CO).