C. Griesinger et al.
(5:1) eluent mixture to yield a yellow solid (1.802 g, 5.4 mmol, 95%).
1H NMR (400 MHz, CDCl3, 258C, TMS): d=8.32 (2H; AA’ part of
AA’XX’), 8.20 (2H; XX’ part of AA’XX’), 7.76 (2H; AA’ part of
AA’XX’), 7.68 (2H; XX’ part of AA’XX’), 7.48–7.36 (m, 5H), 5.40 ppm
(s, 2H); 13C NMR (100 MHz, CDCl3, 258C, TMS): d=166.3, 148.0, 146.7,
143.6, 136.3, 130.9, 130.7, 129.2, 128.9, 128.6, 128.5, 127.7, 124.6,
67.3 ppm; MS (ESI): m/z (%): 334.2 [M+H]+ (100), 242.2 (38); HRMS
(ESI): (CH3OH, NH4OH, positive mode): m/z calcd for C13H8NO4:
242.045334 [M]+; found: 242.0458813.
81.5, 67.0, 65.4, 60.8, 56.9, 54.8, 54.7, 28.6, 28.5, 28.4, 28.3 ppm; MS (ESI):
m/z (%): 1693.1 [2M+H]+ (9), 846.6 [M+H]+ (100), 622.3 (73).
4’-({(R)-2,3-Bis[di(tert-butoxycarbonylmethyl)amino]propionyl}amino)-
1,1’-biphenyl-4-carboxylic acid (6): 4’-({(R)-2,3-Bis-[di(tert-butoxycarbo-
nylmethyl)-amino]propionyl}amino)-1,1’-biphenyl-4-carboxylic
acid
benzyl ester (236.0 mg, 0.28 mmol) was dissolved in methanol (10 mL)
and Pd on charcoal (30%, 5 mg) was added. The mixture was hydrogen-
ated at atmospheric pressure for 5 h, then it was filtered through Celite
and concentrated under reduced pressure. The residue was purified on a
silica gel column with chloroform/methanol (10:1) eluent mixture to
yield a yellow solid (90.6 mg, 0.12 mmol, 43%). 1H NMR (400 MHz,
CDCl3, 258C, TMS): d=8.17 (2H; AA’ part of AA’XX’), 7.83 (2H; XX’
part of AA’XX’), 7.69 (2H; AA’ part of AA’XX’), 7.61 (2H; XX’ part of
4’-Amino-1,1’-biphenyl-4-carboxylic acid benzyl ester (3): A mixture of
4’-nitro-1,1’-biphenyl-4-carboxylic acid benzyl ester (2, 500 mg, 1.5 mmol)
and ethanol was heated to reflux (958C). After about 10 min, iron
powder (837 mg, 0.015 mol) and 1m aqueous HCl solution (0.95 mL)
were added.[47] The mixture was heated at reflux for 4 h, then allowed to
cool to room temperature. The iron was removed by filtration through
Celite and the filtrate was concentrated under reduced pressure. The resi-
due was diluted with ethyl acetate and purified on a silica column with n-
AA’XX’), 3.78 (t, 3J
(m, 3H), 3.03 (dd, 3J
AHCTUNGTRENNUNG
ACHTUNGTRENNUNG
13C NMR (100 MHz, CDCl3, 258C, TMS): d=171.7 (4C), 171.0, 145.9,
139.0, 134.8, 130.7(2C), 127.7, 127.6 (2C), 126.6 (2C), 119.8 (2C), 81.4
(4C), 56.4, 54.4, 49.5, 30.6 ppm (12C); HRMS (ESI): (CH3OH, NH4OH,
positive mode): m/z calcd for C20H17NO2: 756.40659 [M+H]+, 778.38853
[M+Na]+; found: 756.40669, 778.38858.
hexane/ethyl acetate (2:1) eluent mixture to yield
a white solid
(455.0 mg, 1.5 mmol, 71%). M.p. 179–1808C; 1H NMR (400 MHz,
CDCl3, 258C, TMS): d=8.05 (2H; AA’ part of AA’XX’), 7.60 (2H; XX’
part of AA’XX’), 7.46 (2H; AA’ part of AA’XX’), 6.76 (2H; XX’ part of
AA’XX’), 5.38 (s, 2H, COCH2), 3.93 ppm (s, 3H); 13C NMR (100 MHz,
[D6]DMF, 258C, TMS): d=166.7, 150.1, 146.0, 130.0, 127.9, 127.2, 126.6,
125.5, 114.6, 66.9, 51.8 ppm; MS (ESI): m/z (%): 269.2 [M+Na+] (49),
228.1 [M+H+] (100); HRMS (ESI; CH3OH, NH4OH, positive mode): m/
z calcd for C20H17NO2: 304.13321 [M+H]+; found: 304.13316.
1-Azido-1-deoxy-hepta-O-acetyl-b-d-lactopyranoside (7): 1-Azido-1-
deoxy-b-d-lactopyranoside (500 mg, 1.4 mmol) was dissolved in pyridine
(15 mL) and acetic anhydride was added (4.5 mL, 47.7 mmol). The mix-
ture was stirred for 24 h, then extracted with chloroform and 1m aqueous
HCl five times. The organic phase was filtered through MgSO4 and con-
centrated under reduced pressure to give a white solid (918. 2 mg,
1.39 mmol, 99%). 1H NMR (400 MHz, CDCl3, 258C, TMS): d=5.35 (d,
(R)-2,3-Bis[di(tert-butoxycarbonylmethyl)amino] propionic acid (4):[15b]
tert-Butyl bromoacetate (6.83 mL, 9.02 g, 46.2 mmol) was added to a sus-
pension of (R)-2,3-diaminopropionic acid hydrochloride (1.00 g,
7.1 mmol), N-ethyldiisopropylamine (8.52 mL, 6.44 g, 49.8 mmol) and
acetonitrile (50 mL). After heating at reflux for 16 h, additional tert-butyl
bromoacetate (1.05 mL, 1.39 g, 7.1 mmol) and N-ethyldiisopropylamine
(1.22 mL, 0.92 g, 7.1 mmol) were added. The reaction mixture was heated
at reflux for 32 h, cooled, and the solvent was removed under reduced
pressure. The residue was mixed with diethyl ether (100 mL), heated at
reflux for 1 h, cooled, and filtered. The filtrate was washed with 0.1m
phosphate buffer of pH 2.0, dried, and concentrated under reduced pres-
sure. The residue was dissolved in tetrahydrofuran (60 mL), and aqueous
lithium hydroxide (1 moldmꢀ3, 7.1 mL, 7.1 mmol) was added. After stir-
3
3
3J
7.9, 10.4 Hz, 1H), 4.96 (dd, 3J
(H,H)=9.0 Hz, 1H), 4.63 (d, 3J(H,H)=9.0 Hz, 1H), 4.51 (dd, 3J
(H,H)=5.0, 7.9 Hz, 1H), 4.06–4.18 (m,
(H,H)=7.2, 1.9 Hz, 1H), 3.82 (t, 3J
(H,H)=9.0 Hz, 1H),
G
R
ACHTUNGTRENNUNG(H,H)=
AHCTUNGTRENNUNG
G
ACHTUNGTRENNUNG
1.9, 10.5 Hz, 1H), 4.49 (dd, 3J
ACHTUNGTRENNUNG
ACHTUNGTRENNUNG
3.71 (ddd, J
(H,H)=1.9, 5.0, 11.8 Hz, 1H), 2.15 (s, 3H), 2.13 (s, 3H), 2.07
(s, 3H), 2.06 (s, 3H), 2.052 (s, 3H), 2.051 (s, 3H), 1.97 ppm (s, 3H);
13C NMR (100 MHz, CDCl3, 258C, TMS): d=174.6, 170.3, 170.1, 170.0,
169.6, 169.5, 169.1, 101.1, 87.6, 75.7, 74.7, 72.5, 71.0, 70.9, 70.7, 69.0, 66.5,
61.7, 60.7, 21.2 (2C), 20.8, 20.7, 20.6 (2C), 20.4 ppm; MS (ESI): m/z (%):
741.3 [M+pyridine]+ (80), 619.2 (20), 331.1 (100).
1-Amino-1-deoxy-hepta-O-acetyl-b-d-lactopyranoside (8): 1-Azido-1-
deoxy-hepta-O-acetyl-b-d-lactopyranoside (67.8 mg, 0.103 mmol) was dis-
solved in methanol (5 mL), Pd on charcoal (2 mg) was added and the
mixture was hydrogenated for 10 h at atmospheric pressure. The mixture
was filtered through Celite and concentrated under reduced pressure to
give a colourless oil (46.3 mg, 0.073 mmol, 71%). 1H NMR (400 MHz,
ring at room temperature for 3 h, additional aqueous LiOH (1 moldmꢀ3
,
3.6 mL, 3.6 mmol) was added, and stirring was continued for 2 h. Acetic
acid (0.63 mL, 0.66 g, 11 mmol) was added and the solvent was removed
under reduced pressure. Phosphate buffer (0.1 moldmꢀ3, pH 2.0, 40 mL)
was added and the mixture was extracted with chloroform. The organic
phase was dried and concentrated under reduced pressure. The residue
was purified on silica gel with chloroform/methanol (10:1) mixture to
afford 7 (1.52 g, 2.7 mmol, 38%) as a yellowish oil. NMR and mass spec-
trometry data were in agreement with the literature.
CDCl3, 258C, TMS): d=5.34 (d, 3J
(H,H)=9.2 Hz, 1H), 5.08 (dd, 3J(H,H)=8.0, 10.4, 1H), 4.95 (dd, 3J-
(H,H)=3.6, 10.4 Hz, 1H), 4.73 (t, 3J
(H,H)=9.2 Hz, 1H), 4.4–4.55 (m,
2H), 4.03–4.18 (m, 4H), 3.84 (brt, 3J(H,H)=6.4 Hz, 1H), 3.67 (dd, 3J-
(H,H)=9.6, 18 Hz, 1H), 3.60 (dd, 3J
(H,H)=3.2, 10.0 Hz, 1H), 2.15 (s,
(H,H)=2.8 Hz, 1H), 5.20 (t, 3J-
ACHTUNGTRENNUNG
A
ACHTUNGTRENNUNG
A
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
A
ACHTUNGTRENNUNG
4’-({(R)-2,3-Bis[di(tert-butoxycarbonylmethyl)amino]propionyl}amino)-
1,1’-biphenyl-4-carboxylic acid benzyl ester (5): 4’-Amino-1,1’-biphenyl-4-
carboxylic acid benzyl ester (3, 200 mg, 0.66 mmol), HATU, 1-[bis(dime-
3H), 2.12 (s, 3H), 2.06 (s, 12H), 2.05 (s, 3H), 1.96 ppm (s, 3H); 13C NMR
(100 MHz, CDCl3, 258C, TMS): d=172.1 (2C), 170.5, 170.4, 170.3, 170.1,
170.0, 169.6, 169.0, 101.0, 84.6, 76.6, 73.6, 72.9, 72.4, 70.9, 70.6, 69.1, 66.6,
62.3, 60.8, 20.8, 20.7, 20.5 (4CH3), 20.4 ppm; MS (ESI): m/z (%): 636.3
[M+H]+ (100), 576.3 (30), 331.3 (18).
thylamino)-methyliumyl]-1H-1,2,3-triazoloACTHNUTRGNEU[GN 4,5-b]pyridine-3-oxide hexa-
fluorophosphate (300 mg, 0.79 mmol) and (R)-2,3-bis[di(tert-butoxycarbo-
nylmethyl)amino]propionic acid (440 mg, 0.79 mmol) were dissolved in a
mixture of dichloromethane (8 mL) and N-ethyldiisopropylamine
(0.57 mL, 3.3 mmol).[48] The reaction was allowed to run overnight, then
the mixture was extracted with 0.1m aqueous HCl, concentrated and the
residue was purified on a silica gel column with n-hexane/ethyl acetate
(5:1) as eluent, to yield a yellowish oil (523.4 mg, 0.62 mmol, 94%).
1H NMR (400 MHz, CDCl3, 258C, TMS): d=8.11 (2H; AA’ part of
AA’XX’), 7.80 (2H; XX’ part of AA’XX’), 7.64 (2H; AA’ part of
Sugar tag (9): 1-Amino-1-deoxy-hepta-O-acetyl-b-d-lactopyranoside
(65.2 mg, 0.1 mmol), 4’-({(R)-2,3-bis[di(tert-butoxycarbonylmethyl)ami-
no]propionyl}amino)-1,1’-biphenyl-4-carboxylic acid (86.8 mg, 0.1 mmol),
HATU (58.5 mg, 0.15 mmol) and N-ethyldiisopropylamine (87 mL,
0.5 mmol) were dissolved in dichloromethane (5 mL) and the mixture
was stirred for 10 h.[48] The mixture was then purified on a silica gel
column with chloroform/methanol (10:1) eluent mixture to yield the tert-
butoxycarbonyl (Boc) and tBu-protected sugar. HRMS (ESI; CH3OH,
NH4OH, positive mode): m/z calcd for C66H92N4O27: 1373.60217 [M+H]+
; found: 1373.60245. The protected sugar (107 mg, 0.093 mmol) was dis-
solved in dichloromethane (10 mL), and triisopropylsilane (0.3 mL,
0.72 mmol) and water (2 drops) were added followed by the addition of
TFA (1.0 mL, 12.9 mmol) and the mixture was stirred at ambient temper-
ature for 14 h. Following neutralisation with aqueous NaOH (1.0m), the
AA’XX’), 7.58 (2H; XX’ part of AA’XX’), 7.46 (2H; A of ABC), 7.31–
3
7.43 (3H; B and C of ABC), 5.38 (s, 2H), 3.74 (dd, J
N
1H), 3.55–3.62 (m, 6H), 3.47 (d, 3J
(H,H)=17.0 Hz, 1H), 3.37 (dd, 3J(H,H)=5.6, 14.0 Hz, 1H), 3.0 (dd, 3J-
(H,H)=7.6, 14.0 Hz, 1H), 1.46–1.43 ppm (m, 36H); 13C NMR (100 MHz,
(H,H)=17.0 Hz, 1H), 3.42 (d, 3J-
ACHTUNGTRENNUNG
A
ACHTUNGTRENNUNG
ACHTUNGTRENNUNG
CDCl3, 258C, TMS): d=172.1 (2C), 171.8, 171.1 (2C), 166.8, 145.8, 139.4,
136.6, 135.2, 130.6, 129.0, 128.7, 128.6, 128.5, 128.0, 127.0, 120.2, 81.7,
9374
ꢂ 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2011, 17, 9368 – 9376