Nelson et al.
and rapidly stirred for 30 min. The aqueous layer was
extracted with ethyl acetate before being poured onto sodium
hydrogen carbonate (259.8 g, 3.1 M) containing 300 mL of
n-butanol. The butanol layer was removed and the aqueous
layer extracted with butanol. All organic extracts were com-
bined and washed with H2O and once with brine. All solvents
were removed in vacuo and the residue suspended in MeOH
(600 mL) and anhydrous HCl gas was then bubbled in until
dissolution. The solvent was removed in vacuo to a solid, and
triturated with methyl tert-butyl ether. The solid was collected
and washed with diethyl ether followed by hexane. The
compound was dried in vacuo to yield 22.6 g of a light yellow
powder in 69% yield. Analytical Rt ) 11.1, Method B. 1H NMR
(CD3OD, 400 MHz) δ 7.92-7.94 (s, 1H), 4.08 (s, 1H), 3.00 (s,
8H), 2.76 (s, 6H), 2.27 (m, 1H), 2.11 (m, 1H), 1.67 (m, 1H).
HRMS calcd (C23H26IN3O7 + H) 584.0895, found 584.0889.
[4S-(4r,12a r)]-4-(Dim eth yla m in o)-3,10,12,12a -tetr a h y-
d r oxy-7-iod o-1,11-d ioxo-1,4,4a ,5,5a ,6,11,12a -oct a h yd r o-
n a p h th a cen e-2-ca r boxa m id e (6e). A 1.0-g sample of san-
cycline was dissolved in 25 mL of TFA that was cooled to 0
°C. N-Iodosuccinimide (1.2 equiv) was added and reacted for
40 min. The reaction was warmed to room temperature and
reacted for 5 h. The reaction was then driven to completion
by the stepwise addition of NIS (15-mg aliquots) until disap-
pearance of sancycline was noted. Further additions of NIS
resulted in the production of the 7,9-diiodo reaction product
6g. The reaction was stopped by removal of the TFA in vacuo
and the crude solid dissolved in MeOH (5 mL). The solution
was added to cold, rapidly stirred diethyl ether and the
precipitate collected. The solid was dissolved in MeOH, treated
with activated charcoal, and filtered through Celite, and the
solvent was removed in vacuo to produce a yellow solid in 75%
yield. Analytical Rt ) 14.45, Method B. 1H NMR (CD3OD, 300
MHz) δ 7.89 (d, 1H, J ) 8.86 Hz), 6.67 (d, 1H, J ) 8.86 Hz),
3.78 (s, 1H), 3.03 (s, 2H), 2.84 (s, 6H), 2.46 (m, 2H), 0.99 (m,
2H). HRMS calcd (C21H21IN2O7 + H) 541.0474, found 541.0472.
[4S-(4r,12a r)]-4-(Dim eth yla m in o)-3,10,12,12a -tetr a h y-
dr oxy-7,9-diiodo-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octah ydr o-
n a p h th a cen e-2-ca r boxa m id e (6g). Yield 59%. Analytical Rt
) 21.20, Method B. 1H NMR (CD3OD, 300 MHz) δ 8.35 (s, 1H),
3.78 (s, 1H), 3.33 (s, 2H), 2.88 (s, 7H), 2.41 (m, 2H), 0.99-1.41
(m, 2H). HRMS calcd (C24H26N2O7 + H) 666.9438, found
666.9442.
VI. Gen er a l P r oced u r es: Tetr a cyclin e Alk en e a n d
Alk yn e Der iva tives. A 1-mmol sample of iodotetracycline,
50 mg of tetrakistriphenylphosphine palladium(0) catalyst or
equivalent, 12 mg of Pd(OAc)2, and 32 mg of CuI are dissolved
in 10 mL of acetonitrile. Triethylamine (2-5 mL) and 3-5
mmol of alkene, styrene, or alkyne were added and the mixture
was vigorously stirred between room temperature and 70 °C
for 2-24 h. Filtration through Celite and removal of the
solvent in vacuo produced crude products.
5a ,6,11,12a -octa h yd r o-n a p h th a cen e-2-ca r boxa m id e (15).
The purified product was obtained by preparative reverse-
phase HPLC with use of Method C, Rt ) 22-24. Yield 32%.
Analytical Rt ) 15.36, Method A. 1H NMR (CD3OD, 300 MHz)
δ 7.35 (d, 1H, J ) 8.0 Hz), 6.81 (d, 1H, J ) 8.0 Hz), 6.45 (d,
1H, J ) 18.0 Hz), 5.75 (d, 1H, J ) 18.0 Hz), 3.46 (m, 1H), 2.90
(d, each 3H), 2.73 (m, 2H), 2.45 (m, 1H), 1.35 (m, 3H). HRMS
calcd (C25H26N2O10 + H) 511.2080, found 511.2051.
[4S-(4r,12a r)]-4,7-Bis(d im eth yla m in o)-9-(p r op -1-yn yl)-
3,10,12,12a -tetr a h yd r oxy-1,11-d ioxo-1,4,4a ,5,5a ,6,11,12a -
octa h yd r o-n a p h th a cen e-2-ca r boxa m id e (25). The reaction
was performed in a Parr apparatus with all the reagents used
for 24 except that propyne gas was added via a lecture bottle
at -70 °C to 5c, and the Parr apparatus was closed and then
heated at 60 °C for 4 h. The purified product was obtained by
reaction solution filtration, precipitation in diethyl ether, and
further treatment with activated charcoal to yield the product
as a yellow solid in 47% yield. Analytical Rt ) 8.99, Method
B. 1H NMR (CD3OD, 400 MHz) δ 8.23 (s, 1H), 4.20 (s, 1H),
3.13 (s, 6H), 3.08 (s, 6H), 2.89 (s, 6H), 2.71 (s, 3H), 2.45 (m,
1H), 1.74 (m, 1H). HRMS calcd (C24H26N2O7 + H) 496.2086,
found 496.2070.
[4S-(4r,12a r)]-4,7-Bis(d im et h yla m in o)-9-(p h en ylet h -
yn yl)-3,10,12,12a-tetr ah ydr oxy-1,11-dioxo-1,4,4a,5,5a,6,11,-
12a -octa h yd r o-n a p h th a cen e-2-ca r boxa m id e (26). HPLC
yield 74%. The purified product was obtained by preparative
reverse-phase HPLC with use of Method D. Isolated yield 31%.
1
Analytical Rt ) 4.8, Method B. H NMR (CD3OD, 300 MHz) δ
7.84 (s, 1H), 7.34 (m, 2H), 7.20 (s, 3H), 3.93 (s, 1H), 3.02 (s,
6H), 2.87 (s, 6H), 2.26-2.36 (m, 1H), 1.41-1.49 (m, 1H). HRMS
calcd (C31H31N23O7 + H) 558.2240, found 558.2225.
[4S-(4r,12ar)]-7-(2-(E/Z)-Cyan ovin yl)-4-(dim eth ylam in o)-
3,10,12,12a -tetr a h yd r oxy-1,11-d ioxo-1,4,4a ,5,5a ,6,11,12a -
octa h yd r o-n a p h th a cen e-2-ca r boxa m id e (27). The purified
products (E (66%) and Z (33%) isomers) were obtained by
preparative reverse-phase HPLC with use of Method D as a
1
mixture. Total yield 39%. Analytical Rt ) 2.69, Method B. H
NMR (CD3OD, 300 MHz) δ 7.79 (d, J ) 11.7 Hz, Z isomer),
7.76 (m, 1H), 7.36 (d, J ) 16.3 Hz, E isomer), 6.70 (m, 1H),
5.84 (d, J ) 16.3 Hz, E isomer), 3.96 (s, 1H), 3.06 (m, 2H),
2.91 (s, 6H), 2.83 (s, 6H), 1.97-2.22 (m, 4H), 1.31-1.30 (m,
2H). HRMS calcd (C24H23N3O7 + H) 466.1619, found 466.1611.
[4S-(4r,12a r)]-7-Styr yl-4-(d im eth yla m in o)-3,10,12,12a -
tetr a h yd r oxy-1,11-d ioxo-1,4,4a ,5,5a ,6,11,12a -octa h yd r o-
n a p h th a cen e-2-ca r boxa m id e (28). HPLC yield 63.2%. The
purified product was obtained by preparative reverse-phase
HPLC with use of Method D. Isolated yield 30%. Analytical
1
Rt ) 3.98, Method B. H NMR (CD3OD, 300 MHz) δ 7.69 (d,
1H), 7.42 (d, 2H), 7.12-7.40 (m, 4H), 7.15 (d, 1H, J ) 14.4
Hz), 6.78 (d, 1H, J ) 14.4 Hz), 3.99 (s, 1H), 3.1 (s, 1H), 2.95 (s,
6H), 2.85 (s, 6H), 2.30 (m, 1H), 2.08-2.15 (m, 4H), 1.55 (m,
2H). HRMS calcd (C29H28N2O7 + H) 517.1977, found 517.1967.
[4S-(4r, 12a r)]-4-(Dim eth yla m in o)-9-(2-ter t-bu tylca r -
ba m oyl-vin yl)-3,5,10,12,12a -p en ta h yd r oxy-6-m eth yl-1,11-
d ioxo-1,4,4a ,5,5a ,6,11,12a -octa h yd r o-n a p h th a cen e-2-ca r -
boxa m id e (24). 9-Iodo doxycycline (0.9 g, TFA salt, 4f, 1.48
mmol), Pd(OAc)2 (120 mg, 0.53 mmol), and P(o-tolyl)3 (276 mg,
0.9 mmol) with CuI (75 mg) were suspended in acetonitrile
(40 mL) and 1 mL of TEA was added. The solution was
degassed with N2 and stirred at 60 °C for 2 h. HPLC yield
68%. The mixture was cooled to room temperature and filtered
through Celite, and the crude product was obtained after
solvent removal in vacuo. The purified product was obtained
by preparative reverse-phase HPLC with use of Method D in
[4S-(4r,12a r)]-7-[2-(4-Meth yl-th ia zol-5-yl)-vin yl]-4-(d i-
methylamino)-3,10,12,12a-tetrahydroxy-1,11-dioxo-1,4,4a,5,-
5a ,6,11,12a -octa h yd r o-n a p h th a cen e-2-ca r boxa m id e (29).
HPLC yield 46%. The purified product was obtained by
preparative reverse-phase HPLC with use of Method D in 23%
1
yield. Analytical Rt ) 2.56, Method D. H NMR (CD3OD, 300
MHz) δ 9.63 (s, 1H), 7.91 (d, 1H, J ) 9.0 Hz), 7.38 (d, 1H, J )
21.1 Hz), 7.06 (d, 1H, J ) 21.1 Hz), 6.8 (d, 1H, J ) 9.0 Hz),
4.13 (s, 1H), 2.98 (s, 3H), 2.83 (s, 3H), 2.61 (s, 3H), 2.43 (m,
1H), 1.64 (m, 2H). LC/MS (ESI), m/z 538.6.
[4S-(4r,12a r)]-4-(Dim eth yla m in o)-7,9-d ieth yn yl-3,10,-
12,12a -tetr a h yd r oxy-1,11-d ioxo-1,4, 4a ,5,5a ,6,11,12a -oc-
ta h yd r o-n a p h th a cen e-2-ca r boxa m id e (30) a n d [4S-(4r,-
12a r)]-4-(D i m e t h y la m i n o )-7,9-d i e t h y l-3,10,12,12a -
tetr a h yd r oxy-1,11-d ioxo-1,4, 4a ,5,5a ,6,11,12a -octa h yd r o-
n a p h th a cen e-2-ca r boxa m id e (31). A 300-mg sample of
intermediate 6g was dissolved in 20 mL of acetonitrile and
2.0 mL of triethylamine, 50.0 mg of Pd(PPh3)4, 50 mg of CuI,
and 12.5 mg of Pd(OAc)2 were added followed by 0.5 mL of
trimethylsilylacetylene. The reaction was stirred at room
1
47% yield. Analytical Rt ) 3.08, Method B. H NMR (CD3OD,
300 MHz) δ 7.62 (d, 1H, J ) 21.0 Hz), 7.52 (d, 1H, J ) 9.0
Hz), 6.79 (d, 1H, J ) 9.0 Hz), 6.57 (d, 1H, J ) 21.0 Hz), 4.29
(s, 1H), 3.43 (dd, 1H), 2.82 (s, 3H), 2.73 (s, 3H), 2.46 (m, 1H),
1.35 (m, 3H), 1.13 (s, 9H). HRMS calcd (C29H35N3O9 + H)
570.2453, found 570.2453.
[4S-(4r,12a r)]-9-(1′-Cyclop en ten yl)-4-(d im eth yla m in o)-
3,5,10,12,12a -p en ta h yd r oxy-6-m eth yl-1,11-d ioxo-1,4,4a ,5,-
5848 J . Org. Chem., Vol. 68, No. 15, 2003