Novel Benzophenones as Non-nucleoside Reverse Transcriptase Inhibitors of HIV-1

Article abstract of DOI:10.1021/jm030255y

GW4511, GW4751, and GW3011 showed IC₅₀ values ≤2 nM against wild type HIV-1 and <10 nM against 16 mutants. They were particularly potent against NNRTI-resistant viruses containing Y181C-, K103N-, and K103N-based double mutations, which account for a significant proportion of the clinical failure of the three currently marketed NNRTIs. The antiviral data together with the favorable pharmacokinetic data of GW4511 suggested that these benzophenones possess attributes of a new NNRTI drug candidate.

Full text of DOI:10.1021/jm030255y

J . Med. Chem. 2004, 47, 1175-1182
1175
Novel Ben zop h en on es a s Non -n u cleosid e Rever se Tr a n scr ip ta se In h ibitor s of
HIV-1
J oseph H. Chan,* George A. Freeman, J effrey H. Tidwell, Karen R. Romines, Lee T. Schaller, J ill R. Cowan,
Steve S. Gonzales, Gina S. Lowell, C. W. Andrews III, David J . Reynolds, Marty St Clair, Richard J . Hazen,
Rob G. Ferris, Katrina L. Creech, Grace B. Roberts, Steven A. Short, Kurt Weaver, George W. Koszalka, and
Lawrence R. Boone
GlaxoSmithKline Inc., 5 Moore Drive, Research Triangle Park, North Carolina 27709
Received May 27, 2003
GW4511, GW4751, and GW3011 showed IC50 values e2 nM against wild type HIV-1 and <10
nM against 16 mutants. They were particularly potent against NNRTI-resistant viruses
containing Y181C-, K103N-, and K103N-based double mutations, which account for a significant
proportion of the clinical failure of the three currently marketed NNRTIs. The antiviral data
together with the favorable pharmacokinetic data of GW4511 suggested that these benzophe-
nones possess attributes of a new NNRTI drug candidate.
In tr od u ction
Highly active antiretroviral therapy (HAART) com-
bination regimens have dramatically decreased the
morbidity and mortality among patients with human
immunodeficiency virus (HIV) infections.1 HAART regi-
mens typically consist of two nucleoside reverse tran-
scriptase inhibitors (NRTIs) and either a protease
inhibitor (PI) or a non-nucleoside reverse transcriptase
inhibitor (NNRTI) as a third agent, or three NRTIs. The
NNRTI class is the least extensive in terms of approved
agents, consisting of only three, nevirapine,2 delavird-
ine,3 and efavirenz4 (Figure 1).
NNRTIs bind in a region of HIV-1 RT which is
approximately 10 Å away from the catalytic site. Unlike
the nucleosides, which require anabolism to the triph-
F igu r e 1. Currently approved NNRTIs.
osphate to become chain-terminating substrates, NNR-
TIs bind directly to the enzyme and inhibit catalytic
function by distorting the three-dimensional structure
of HIV-1 RT.5 Hampered by the rapid emergence of
resistant viruses in monotherapy, the therapeutic use-
fulness of NNRTIs was not fully realized until combina-
tion therapy with NRTIs and PIs proved successful in
lowering viral load.6,7 Subsequently, there has been a
revived interest in developing NNRTIs to treat HIV
infections and AIDS.
Current NNRTIs have a relatively low genetic barrier
to mutations, and consequently resistance emerges quite
rapidly. This and high cross-resistance within the class
dictate that a new generation NNRTI should exhibit
high potency against both wild-type and resistant
strains of the virus.
To date, several attempts to describe such a compound
have been made. A series of benzophenone analogues
with potent activity against wild-type HIV-1 has been
reported.8 From an initial structure 4 (Figure 2),
compound 5 (Figure 2) was identified as having the
requisite pharmacophore for antiviral activity. Unfor-
F igu r e 2. Early benzophenones.
tunately, passage experiments with analogue 6 (Figure
2) resulted in the rapid emergence of an HIV-1 resistant
strain. Although the observed mutation was not the
highly cross-resistant Y181C, nonetheless, these ben-
zophenones were precluded from considerations as
therapeutics because of the rapid emergence of that
mutation.8
* To whom correspondence should be addressed. Current address:
GlaxoSmithKline K.K., Tsukuba Research Labs., 43 Wadai, Tsukuba-
shi, Ibaraki 300-4247. Phone: +81-29-864-5545. Fax +81-29-864-8558.
E-mail: joe.h.chan@gsk.com.
10.1021/jm030255y CCC: $27.50 © 2004 American Chemical Society
Published on Web 01/30/2004

1176 J ournal of Medicinal Chemistry, 2004, Vol. 47, No. 5
Chan et al.
F igu r e 3. Current potent benzophenones.
Sch em e 1a
bonyldiimiazole (CDI) and triethylamine. Intermediate
14 was then reacted with the lithium salt of 2-bromo-
4-chloroanisole resulting in 15. Demethylation using
boron tribromide in methylene chloride led to hydroxy
benzophenone 16 that was then reacted with ethyl
bromoacetate to give ester 17. On saponification, 17 led
to acid 18 from which acid chloride 10a was generated
in situ by the reaction of 18 with a Vilsmeier-Haack
reagent generated from oxalyl chloride and DMF.10
The synthesis of aniline 11 is depicted in Scheme 3
and began by protection of 2-aminotoluene-5-sulfonic
acid with acetic anhydride, leading to pyrdinium salt
19. Salt exchange of 19 with sodium hydroxide led to
20. Sulfonyl chloride 21 was generated in situ after
reacting sodium salt 20 with thionyl chloride in DMF.
21 was then reacted with ammonium hydroxide in THF
to afford 22.11 Deprotection with concentrated hydro-
chloric acid in refluxing aqueous ethanol led to 11.
a
Conditions: (a) NaHCO3, acetone, H2O, reflux.
Sch em e 2a
The acid chloride 10b for the synthesis of compound
8 was synthesized as shown in Scheme 4. 3-Cyanoben-
zoyl chloride, prepared from commercially purchased
3-cyanobenzoic acid with oxalyl chloride in methylene
chloride and catalytic DMF, was reacted with N,O-
dimethylhydroxylamine hydrochloride in chloroform and
triethylamine to afford the desired Weinreb amide 23.
The amide was reacted, as before, with the lithium salt
of 2-bromo-4-chloroanisole leading to intermediate 24.
Demethylation with boron tribromide resulted in phenol
25, which was then reacted with ethyl bromoacetate
using potassium carbonate as the base leading to ester
26. Hydrolysis of the ester group with lithium hydroxide
led to the carboxylic acid 27. Acid chloride 10b was
generated in situ under conditions similar to those
described above for 10a .
a
Conditions: (a) CDI, NH(OMe)Me‚HCl, TEA, THF, 0 °C to
rt; (b) n-BuLi, THF, 78 °C, 14; (c) BBr3, CH2Cl2, -78 °C to rt; (d)
K2CO3, DMF, BrCH2CO2Et, reflux; (e) LiOH, H2O, EtOH, rt; (f)
(COCl)2, DMF, CHCl3, 0 °C to rt.
In this paper we describe synthetic work and struc-
ture-activity relationship studies, aided by computer
modeling of the X-ray crystal structures of the ben-
zophenone-RT complex.9 This work had resulted in the
identification of a series of analogues that were potent
against wild-type HIV-1 and a panel of NNRTI-resistant
HIV-1 strains. GW4511, GW4751, and GW3011 (Figure
3) were examples of such analogues, which showed
broad-spectrum potency and could be considered im-
portant lead molecules in the discovery of a new
generation NNRTI.
Finally, the synthesis of aniline 12 followed the
procedures described in Scheme 5. Commercially pur-
chased 3-methyl-4-nitrophenol was reacted with 1,3-
propane sultone using sodium hydride as the base. This
resulted in intermediate 28, which was then reacted
with thionyl chloride to give chloride 29. Upon reacting
with ammonium hydroxide in THF, 30 was formed,
which was hydrogenated in a Parr bomb leading to
aniline 12.
Ch em istr y
The key step in the synthesis involved the coupling
of acid chloride 10a , 10b, and aniline 11 for the
synthesis of benzophenones 7 and 8, and the coupling
of acid chloride 10a and aniline 12 for the synthesis of
compound 9, as depicted in Scheme 1.8
Acid chloride 10a (R ) F, R′ ) CF3) for the synthesis
of 7 was synthesized according to procedures sum-
marized in Scheme 2. The first step involved the
synthesis of Weinreb amide 14 from benzoic acid 13 with
N,O-dimethylhydroxylamine hydrochloride using car-
Resu lts a n d Discu ssion
During the initial stages of our search for a lead
molecule, we routinely evaluated compounds in an MT4
cell assay infected with wild-type virus or Y181C, a
nevirapine- and delavirdine-resistant strain.12 Ben-
zophenones GW4751, GW4511, and GW3011 were evalu-
ated initially for their antiviral activity in such an assay,

Benzophenone Reverse Transcriptase Inhibitors of HIV-1
J ournal of Medicinal Chemistry, 2004, Vol. 47, No. 5 1177
Sch em e 3a
a
Conditions: (a) Ac2O, pyridine, rt; (b) 1 N NaOH, 0 °C; (c) SOCl2, DMF, -4 °C; (d) NH4OH, THF, rt; (e) concd HCl, EtOH, H2O,
reflux.
Sch em e 4a
a
Conditions: (a) n-BuLi, Et2O, -78 °C to rt; (b) BBr3, CH2Cl2, -78 °C to rt; (c) BrCH2CO2Et, K2CO3, acetone, reflux; (d) LiOH, THF,
EtOH, H2O, rt; (e) (COCl)2, DMF, CHCl3, 0 °C to rt.
Sch em e 5a
a
Conditions (a) NaH, THF, 0 °C to reflux; (b) SO2Cl2, 0 °C to rt; (c) NH4OH, THF3, 0 °C; (d) H2, Pd/C, EtOH, rt.
Ta ble 1. Antiviral Activity of GW4751, GW4511, GW3011, and Marketed NNRTIs in MT4 Cells Infected with HIV-1
IC50 values (nM) vs wild-type HIV-1 and Y181C strain
virus
GW4751
GW4511
GW3011
nevirapine
delavirdine
efavirenz
wild-type
Nev-R
1.8
1.4
0.5
1.6
7.2
4.5
96
17200
160
2400
3.5
2.7
Ta ble 2. Activity of GW4511, GW4751, and GW3011 against Wild-Type Reverse Transcriptase
IC50 values [nM] (n)a
RT enzyme
wild-type
GW4511
3.0 (4)
GW4751
1.7 (4)
GW3011
4.7 (4)
efavirenz
0.75 (4)
nevirapine
230 (4)
delavirdine
21 (3)
a
Efavirenz, nevirapine, and delavirdine are included for comparison purposes.
and the results are summarized in Table 1. Nevirapine,
delavirdine, and efavirenz are included in the table for
comparison purposes.
The NNRTI-resistant strains (Table 3) were con-
structed using the procedure of Kellam and Larder14
and encode both single and double mutations surround-
ing the NNRTI binding site. Some of these mutations
are known to manifest high NNRTI cross-resistance. For
example, K103N and Y181C confer a high degree of
cross-resistance to the currently available NNRTIs and
signal the loss of clinical efficacy.15
Resistance to nevirapine is directly linked to K103N
and Y181C mutations, as well as mutants encoding the
G190A, Y188C/I, L100I, and V106A mutations.16,17
Delavirdine is limited in use by K103N, Y181C, and
P236L mutations.18 This background information and
that obtained from the resistance profiles of other
NNRTIs19 were used to construct the 20 mutant viruses
shown in Table 3.
The results of this preliminary assay suggest that all
three benzophenone analogues were potent compounds.
Indeed, GW4751, GW4511, and GW3011 were much
more potent than nevirapine and delavirdine and
equivalent to efavirenz against both the wild-type virus
and Y181C. We next assayed the three compounds
against HIV-1 reverse transcriptase, and the data are
listed in Table 2.
The inhibitory activity against HIV-1 RT indeed
showed the mechanism of action of those three com-
pounds was via the inhibition of HIV-1 RT and the
enzyme activity consistent with the antiviral activity
shown in Table 1.13 These results warranted further
evaluation against a more extensive panel of NNRTI-
resistant strains, including those highly resistant to
efavirenz using a HeLa MAGI luciferase reporter as-
say.12
GW4751, GW4511, and GW3011 were found to be
extremely potent against the wild-type virus with IC50
values e2 nM. Against 16 of the 20 mutants, the three
compounds showed IC50 values of <10 nM. Four of these

1178 J ournal of Medicinal Chemistry, 2004, Vol. 47, No. 5
Chan et al.
Ta ble 3. Antiviral Activity of GW4511, GW4751, and GW3011 against Wild-type HIV-1 and a Panel of Resistant HIV-1 Strains
IC50 Values [nM] (n)a
HIV-1 type
GW4511
GW4751
GW3011
efavirenz
nevirapine
delavirdine
wild-type
K103N
V106A
V106I
V108I
K101E
L100I
G190A
P225H
P236L
Y181C
Y188C
E138K
K103N/Y181C
K103N/P225H
K103N/G190A
K103N/L100I
K103N/V108I
V106A/Y181C
V106I/Y181C
V108I/Y181C
1.4 (30)
1.9 (25)
10.0 (25)
2.5 (9)
1.9 (8)
3.4 (3)
1.2 (6)
4.2 (8)
0.7 (7)
5.1 (6)
1.4 (12)
2.0 (10)
30.0 (6)
2.7 (4)
1.0 (4)
3.4 (4)
0.8 (4)
5.2 (4)
0.5 (3)
21 (2)
6.5 (3)
0.3 (6)
3.9 (3)
8.1 (6)
3.0 (4)
26 (5)
2.4 (8)
3.3 (9)
16 (4)
3.2 (3)
3.5 (3)
7.2 (3)
2.0 (3)
5.6 (3)
1.8 (3)
7.8 (2)
6.6 (2)
0.6 (4)
6.1 (3)
7.6 (6)
7.9 (5)
15 (3)
6.6 (5)
4.8 (6)
21 (5)
11 (4)
6.2 (3)
0.9 (30)
27 (34)
1.5 (22)
0.8 (10)
2.1 (11)
2.5 (8)
21 (14)
7 (13)
1.7 (7)
100 (14)
6600 (11)
9000 (10)
150 (4)
290 (7)
520 (3)
200 (9)
2700 (7)
,900 (4)
55 (3)
78 (3)
29 (2)
920 (2)
35 (2)
11 (3)
500 (3)
>10 000 (6)
1200 (1)
0.8 (9)
56 (2)
1,600 (2)
2300 (1)
170 (4)
3.1 (11)
0.4 (9)
3.0 (6)
1.8 (17)
1.4 (11)
0.9 (8)
9400 (13)
2300 (10)
65 (6)
10 (1)
3.6 (14)
1.5 (12)
16.0 (10)
3.0 (10)
3.6 (10)
16 (14)
11 (12)
3.4 (12)
46 (21)
150 (14)
490 (11)
1,500 (18)
93 (14)
3.1 (8)
>10 000 (11)
>8400 (5)
2300 (4)
2700 (3)
> 8400 (5)
3500 (3)
>10 000 (2)
4500 (4)
>10 000 (1)
9800 (6)
>10 000 (3)
8000 (8)
15000 (7)
>10 000 (2)
>10 000 (3)
>10 000 (3)
4.0 (5)
5.6 (5)
28 (4)
34 (5)
4.1 (2)
3.6 (8)
3.1 (6)
a
Efavirenz, nevirapine, and delavirdine are included for comparison purposes.
Ta ble 4. Protein Binding Studies in HeLa MAGI Assay
Ta ble 5. Mean Pharmacokinetic Parameter Values for
GW4511 Following Single Oral Dose Administration to Rats,
Dogs, and Monkeys
fold change in IC50
HXB2
K103N
AUCc
Fd
a
b
dose
Cmax
C24h
NNRTI AAGa HuSb AAG + HuS AAG HuS AAG + HuS
species (mg/kg) formulation (ng/mL) (ng/mL) (ng h/mL) (%)
GW4751
GW4511
GW3011
EFV
1.1
1.9
1.7
2.4
1.0
6.4
7.7
5.5
24
2.5
3.7
6.5
7.7
20
2.0
1.9
1.4
1.5
1.3
0.8
4.5
5.8
5.7
5.1
1.0
2.4
5.5
5.3
5.8
1.2
rat
10
1
solution
suspension
solution
suspension
solution
suspension
357
60
80
22
95
4
32
nde
nd
7
8
nd
4146
438
650
451
988
57
27
3
29
20
58
3
dog
NEV
monkey
1
a
b
AAG, 0.8 mg/mL a1 acid glycoprotein. HuS, 45% human
a
b
serum.
Cmax, maximum observed concentration in plasma. C24h,
concentration in plasma at 24 h postdose. c AUC, area under the
plasma concentration-time curve. F, oral bioavailability [(AUCpo
AUCiv) × 100]. e nd, not determined or not detected (i.e., <1 ng/
mL).
d
/
mutants are K103N-based including K103N/P225H and
K103N/L100I, which are highly resistant to efavirenz.
The highest IC50 values in the entire panel were 16 nM
for GW4511 (vs K103N/G190A and V106A/Y181C), 21
nM for GW3011 (vs V106A/Y181C), and 34 nM for
GW4751 (vs V106I/Y181C).
advantage in Cmax and exposures relative to the suspen-
sions (compound suspended in aqueous 5% hydroxy-
propylmethylcellulose (HPMC):Tween-80). The total
body clearance values (Cl), determined from single
intravenous administration were 11, 7, and 10 mL/min/
kg for the rat, dog, and monkey, respectively. The
calculated Cl values were consistently less than one-
third of hepatic blood flow for all three species, indicat-
ing an acceptable metabolic fate and clearance of the
drug from the body. The oral bioavailability (F) ranged
from 27 to 58% when the drug was administered as a
solution and 3-20% when it was dosed as a suspension.
In summary, we have identified a benzophenone
scaffold, analogues of which showed potent broad-
spectrum antiviral activity against both wild type and
relevant NNRTI-resistant mutant viruses. GW4751,
GW4511, and GW3011 were three of the analogues that
manifested potency against the wild type HIV-1 and the
panel of NNRTI-resistant mutants. Of particular sig-
nificance was their potency against the Y181C-, K103N-,
and K103N-containing double mutation NNRTI-resis-
tant viruses, which account for a significant proportion
of the clinical failure of the three currently marketed
NNRTIs. The pharmacokinetic data, together with the
potency and broad-spectrum antiviral activity, sug-
gested that these benzophenones are potentially impor-
tant lead molecules for a new generation NNRTI.
The effect of protein binding on the antiviral activity
of GW4751, GW4511, and GW3011 versus both the wild-
type virus (strain HXB2) and the K103N resistant strain
was tested in the presence of acid glycoprotein, human
serum, and a combination of both acid glycoprotein and
human serum. The results are summarized in Table 4,
together with those for efavirenz and nevirapine. As
shown in the table, the presence of acid glycoprotein had
limited affect on the antiviral activity of GW4751,
GW4511, and GW3011 versus both the wild-type virus
and the K103N resistant strain, similar to that observed
for both efavirenz and nevirapine. In the presence of
human serum, the fold change in IC50 was still within
a reasonable range, albeit slightly higher than that in
acid glycoprotein. The combination of acid glycoprotein
and human serum did not have a dramatic effect on the
antiviral activity.
In an effort to establish putative developability of the
benzophenone class, GW4511 was administered to rats,
dogs, and monkeys to determine its pharmacokinetic
characteristics. The results of those experiments are
summarized in Table 5. Each species provided evidence
of absoprtion with both solutions and suspensions. The
solutions of drug in PEG400 consistently demonstrated

Benzophenone Reverse Transcriptase Inhibitors of HIV-1
J ournal of Medicinal Chemistry, 2004, Vol. 47, No. 5 1179
[4-C h lo r o -2-(3-flu o r o -5-t r iflu o r o m e t h y lb e n zo y l)-
ph en oxy]acetic Acid (18). A round-bottom flask was equipped
with a stir bar and nitrogen on demand and was flushed with
N2. To the flask were added LiOH (1.42 g, 33.84 mmol), H2O
(20 mL), THF (50 mL), and EtOH (20 mL). The resulting
suspension was stirred vigorously, and 17 (6.83 g, 16.88 mmol)
was added in one portion. The mixture was allowed to stir at
room temperature for 2 h, after which the pH was adjusted to
approximately pH 5 by the slow addition of 1 N aq HCl. The
mixture was then poured into a separatory funnel containing
EtOAc and H2O. The organic layer was collected and was
washed with water and brine. After drying (MgSO4) and
solvent removal, 18 was obtained as a white solid. The solid
was used in the following reaction without further purification.
[4-C h lo r o -2-(3-flu o r o -5-t r iflu o r o m e t h y lb e n zo y l)-
p h en oxy]a cetyl Ch lor id e (10a ). Into a round-bottom flask
were placed carboxylic acid 18 (11.24 g, 29.84 mmol), CH2Cl2
(250 mL), and DMF (5 mL). The mixture was cooled to 0 °C,
and oxalyl chloride (3.9 mL, 44.7 mmol) was added dropwise.
The reaction mixture was allowed to warm to room temper-
ature and stir for 2 h. The solvents were then removed under
reduced pressure, and the remaining residue was dried in
vacuo. The acid chloride thus obtained was used without
further purification
P yr idin iu m 4-(Acetylam in o)-3-m eth ylben zen esu lfon ate
(19). Into a round-bottom flask with argon on demand and an
overhead stirrer were placed 2-aminotoluene-5-sulfonic acid
(250 g, 1.34 mol) and pyridine (1.7 L). Acetic anhydride (205
mL, 2.17 mol) was added dropwise from an addition funnel,
and the resulting mixture was allowed to stir for 2 h. The
solvents were removed in vacuo and further azeotroped with
several portions of EtOH. EtOH was re-added and the result-
ing suspension was cooled in an ice water bath and filtered.
The solid obtained was washed with cold EtOH and Et2O and
then dried in vacuo to afford 19 as a pink solid (366.80 g, 89%).
1H NMR (DMSO-d6, 300 MHz) δ 2.04 (s, 3H), 2.17 (s, 3H), 7.35
(s, 2H), 7.41 (s, 1H), 8.04 (t, J ) 7 Hz, 2H), 8.57 (t, J ) 8 Hz,
1H), 8.91 (d, J ) 5 Hz, 2H), 9.27 (s, 1H).
Exp er im en ta l Section
1H NMR spectra were recorded on a Varian XL200, Varian
Unity Plus 400, or Varian Unity Plus 200 MHz spectrometers.
Elemental analyses were carried out by Atlantic Microlabs,
Inc., Atlanta, GA. All purchased starting materials were used
without further purifications. All solvents were reagent grades.
Procedures for the MT4 cell assay and the HeLa MAGI assay
followed that described in ref 12.
3-F lu or o-N -m e t h oxy-N -m e t h yl-5-(t r iflu or om e t h yl)-
ben za m id e (14). Into a round-bottom flask equipped with a
stir bar and nitrogen on demand were placed N,O-dimethyl-
hydroxylamine hydrochloride (2.8 g, 28.7 mmol), Et3N (9.0 mL,
64.57 mmol), and CHCl3 (50 mL). The solution was cooled to
0 °C, and 3-trifluoromethyl-5-fluorobenzoyl chloride (5.0 g,
22.07 mmol) was added dropwise over several minutes. The
resulting solution was allowed to stir at 0 °C for 30 min, after
which time it was allowed to warm to room temperature and
stirred for an additional 30 min. The mixture was then poured
into a separatory funnel containing EtOAc and H2O. The
organic layer was collected and washed with water and brine.
After drying (MgSO4) and solvent removal, 14 was obtained
as a clear oil, which was used without any further purification.
1H NMR (CDCl3, 300 MHz) δ 7.83 (s, 1H), 7.65 (d, J ) 9 Hz,
1H), 7.46 (d, J ) 9 Hz, 1H), 3.59 (s, 3H), 3.42 (s, 3H).
(5-Ch lor o-2-m et h oxyp h en yl)[3-flu or o-5-(t r iflu or om e-
th yl)p h en yl]m eth a n on e (15). Into a round-bottom flask
equipped with a stir bar and nitrogen on demand were placed
2-bromo-4-chloroanisole (4.05 g, 18.29 mmol) and Et2O (75
mL). The solution was cooled to -78 °C, and n-BuLi (13 mL
of a 1.6 M solution in hexane, 20.8 mmol) was added dropwise.
The resulting mixture was allowed to stir at -78 °C for 15
min, after which 14 (5.04 g, 20.07 mmol) was added dropwise.
After stirring for an additional 30 min at - 78 °C, the reaction
mixture was allowed to warm to room temperature and
stirring was continued for an additional 2 h. The mixture was
then poured into a separatory funnel containing EtOAc and
H2O. The organic layer was collected and was washed with
water and brine. After drying (MgSO4) and solvent removal,
15 was obtained as a yellow solid (6.14 g, 92%), which was
used in the following reaction without any further purification.
1H NMR (CDCl3, 300 MHz) δ 7.84 (s, 1H), 7.68 (d, J ) 9 Hz,
1H), 7.58-7.51 (m, 2H), 7.44 (d, J ) 3 Hz, 1H), 7.00 (d, J ) 9
Hz, 1H), 3.74 (s, 3H).
Sod iu m 4-(Acet yla m in o)-3-m et h ylb en zen esu lfon a t e
(20). NaOH (1 N) (1.25 L) was added to a around-bottom flask
and cooled to 0 °C. 19 (367 g, 1.2 mol) was added portionwise,
and the resulting mixture was allowed to warm to room
temperature. EtOH was added, and the mixture was concen-
trated under reduced pressure by 75%. An additional portion
of EtOH was added, and the mixture was then concentrated
to dryness in vacuo. The solid was triturated with EtOH,
filtered, washed with Et2O, and dried in vacuo overnight to
(5-Ch lor o-2-h yd r oxyp h en yl)[3-flu or o-5-(tr iflu or om eth -
yl)p h en yl]m et h a n on e (16). Into a round-bottom flask
equipped with a stir bar and nitrogen on demand were placed
15 (6.14 g, 18.46 mmol) and CH2Cl2 (100 mL). The solution
was cooled to -78 °C, and boron tribromide (50 mL of a 1.0 M
solution in CH2Cl2, 50 mmol) was added dropwise over several
min. The resulting dark mixture was allowed to stir at -78
°C for 30 min and was then allowed to warm to room
temperature and stir for an additional 1 h. The mixture was
carefully poured over ice, and the two-phase mixture was
stirred for 30 min. The mixture was then poured into a
separatory funnel containing CH2Cl2 and H2O. The organic
layer was collected and washed with water and brine. After
drying (MgSO4) and solvent removal, 16 was obtained as a
yellow solid (5.68 g, 96%), which was used without any further
1
afford 20 as an off-white solid (296 g, 99%). H NMR (DMSO-
d6, 400 MHz) δ 2.04 (s, 3H), 2.18 (s, 3H), 7.37 (s, 2H), 7.43 (s,
1H), 9.30 (s, 1H).
N-[4-(Am in osu lfon yl)-2-m eth ylp h en yl]a ceta m id e (22).
20 (205 g, 820 mmol) and DMF (1.6 L) were added to a round-
bottom flask that was equipped with a stir bar and N2 on
demand and was cooled to -4 °C in an ice-brine bath. Thionyl
chloride (180 mL, 2.5 mol) was added dropwise from an
addition funnel at a rate that the temperature of the reaction
mixture did not exceed 0 °C. When the addition was complete,
the mixture was kept below 0 °C and allowed to stir for an
additional 2 h. The mixture was then poured into a beaker
containing crushed ice and H2O (3 L). The resulting yellow
solid was collected by filtration, washed with several portions
of H2O, and dried under a stream of nitrogen. The solid was
then added portionwise to a stirred solution of THF (1.6 L)
and concentrated NH4OH (850 mL). The reaction was then
stirred for 20 min. and concentrated in vacuo and triturated
with cold H2O. The solid obtained was filtered and washed
with Et2O. After drying in vacuo, 22 was obtained as a tan
solid (189.48 g, crude product). 1H NMR (DMSO-d6, 400 MHz)
δ 2.09 (s, 3H), 2.27 (s, 3H), 7.25 (s, 2H), 7.58 (dd, J ) 2, 8 Hz,
1H), 7.64 (d, J ) 2 Hz, 1H), 7.69 (d, J ) 8 Hz, 1H), 9.44 (s,
1H).
1
purification. H NMR (CDCl3, 300 MHz) δ 11.61 (s, 1H), 7.77
(s, 1H), 7.65-7.54 (m, 3H), 7.47 (d, J ) 3 Hz, 1H), 7.12 (d, J
) 9 Hz, 1H).
Eth yl [4-Ch lor o-2-(3-flu or o-5-tr iflu or om eth ylben zoyl)-
p h en oxy]a ceta te (17). Into a round-bottom flask equipped
with a stir bar, reflux condenser, and nitrogen on demand were
placed 16 (5.68 g, 17.83 mmol), ethyl bromoacetate (2 mL,
18.03 mmol), K2CO3 (9.61 g, 69.53 mmol), and acetone. The
resulting mixture was heated to reflux for 5 h, after which it
was allowed to cool to room temperature and was poured into
a separatory funnel containing EtOAc and H2O. The organic
layer was collected and was washed with water and brine.
After drying (MgSO4) and solvent removal, 17 was obtained
as an oil, which was used in the following reaction without
further purification.
4-Am in o-3-m eth ylben zen esu lfon am ide (11). Into a round-
bottom flask equipped with a stir bar and N2 on demand were
placed 22 (127 g, 560 mmol), H2O (65 mL), and EtOH (1200

1180 J ournal of Medicinal Chemistry, 2004, Vol. 47, No. 5
Chan et al.
mL). Concentrated HCl (500 mL) was added, and the mixture
was brought to reflux for 1 h. The reaction mixture was cooled
to room temperature, quenched with sat. NaHCO3 and ex-
tracted with EtOAc (3×). The organic layer was washed with
water and brine, dried over MgSO4, filtered, and concentrated
in vacuo to afford 11 (70.24 g, 68%) as a tan solid. 1H NMR
(DMSO-d6, 300 MHz) δ 2.07 (s, 3H), 5.57 (s, 2H), 6.61 (d, J )
8 Hz, 1H), 6.85 (s, 2H), 7.32 (dd, J ) 2, 8 Hz, 1H), 7.36 (d, J
) 2 Hz, 1H).
[4-Ch lor o-2-(3-cya n oben zoyl)p h en oxy]a cetic Acid (23).
A round-bottom flask was flushed with N2 and equipped with
a stir bar and N2 on demand. To the flask were added 22 (120
g, 0.35 mol), H2O (200 mL), THF (800 mL), EtOH (200 mL),
and lithium hydroxide (120 g, 0.35 mol). The resulting suspen-
sion was stirred vigorously for 2 h, after which the pH was
adjusted to approximately 3 by the slow addition of concen-
trated HCl. The mixture was then poured into a separatory
funnel containing EtOAc. The organic layer was collected and
was dried over MgSO4. After solvent removal, a crude solid
was obtained, which was triturated with pentane and then
dried in a vacuum oven at room temp for 2 h. This resulted in
N-[4-(Am in osu lfon yl)-2-m et h ylp h en yl]-2-{4-ch lor o-2-
[3-flu or o-5-(t r iflu or om e t h yl)b e n zoyl]p h e n oxy }a ce t -
a m id e (7). Into a round-bottom flask were placed sulfonamide
11 (5.12 g, 27.49 mmol), NaHCO3 (11.12 g, 132 mmol), acetone
(300 mL), and H2O (10 mL). 10a was added dropwise as a
solution in acetone (10 mL), and the reaction mixture was
allowed to stir at room temperature for 24 h. When judged to
be complete, the mixture was poured into a separatory funnel
containing EtOAc and H2O. The organic layer was collected
and was washed with water and brine. After drying (MgSO4)
and solvent removal, 7 was obtained as a white solid (9 g, 60%)
1
23 (103 g, 94%) as a white solid. H NMR (400 MHz, DMSO-
d6) δ 12.24 (bs, 1H), 8.09 (s, 1H), 8.04 (m, 2H), 7.66 (t, J ) 8
Hz, 1 H), 7.55 (dd, J ) 4, 8 Hz, 1 H), 7.43 (m,1 H), 7.08 (d, J
) 8 Hz, 1H), 4.62 (s, 2H).
N-[4-(Am in osu lfon yl)-2-m et h ylp h en yl]-2-[4-ch lor o-2-
(3-cya n oben zoyl)p h en oxy]a ceta m id e (8). Into a round-
bottom flask were placed 23 (100 g, 320 mmol) and CH2Cl2 (1
L). The mixture was cooled in an ice water bath. Oxalyl
chloride (44.4 g, 350 mmol) was added dropwise. After 15 min,
DMF (1 mL) was added, and the reaction mixture was allowed
to stir at room temperature for 2 h. An additional amount of
oxalyl chloride (2 equiv) and DMF (1 mL) were added, and
the reaction again was stirred at room temperature for 2 h.
When judged to be complete, the homogeneous solution was
concentrated in vacuo. Into another round-bottom flask were
placed 11 (54 g, 290 mmol), acetone (1 L), NaHCO3 (134 g, 1.6
mol), and H2O (∼80 mL). The acid chloride from above was
dissolved in reagent grade acetone (250 mL) and added
dropwise over 30 min. The reaction was allowed to stir at room
temperature overnight before the mixture was poured into a
separatory funnel containing EtOAc (500 mL) and H2O (500
mL). The white solid formed was filtered. The organic layer
was separated, dried over MgSO4,and filtered. Concentration
of the organic layer afforded an off-white solid. The desired
product was obtained by combining the two solids, recrystal-
lization from a mixture of CH3CN/ H2O (3:2), and vacuum-
1
after crystallization from a mixture of CH3CN/H2O. H NMR
(DMSO-d6, 300 MHz) δ 9.47 (s, 1H), 8.05 (d, J ) 9 Hz, 1H),
7.93-7.90 (m, 2H), 7.73-7.50 (m, 5H), 7.30-7.26 (m, 3H), 4.84
(s, 2H), 2.19 (s, 3H). Anal. Calcd for C23H17ClF4N2O5S: C,
50.70; H, 3.14; N, 5.14. Found: C, 50.75; H, 3.10; N, 5.21.
3-(5-Ch lor o-2-m eth oxyben zoyl)ben zon itr ile (20). To a
round-bottom flask equipped with an overhead stirrer, an
addition funnel, and N2 on demand were placed 2-bromo-4-
chloroanisole (75.3 g, 0.34 mol) and Et2O (800 mL). The
mixture was cooled to -78 °C, and n-BuLi (148 mL of a 2.5 M
solution in hexane, 0.37 mol) was added dropwise via the
addition funnel. The reaction was then allowed to stir at -78
°C for 1 h. 19 (65 g, 0.34 mol) was added dropwise as a solution
in Et2O (150 mL) over 30 min. The reaction was warmed to
room temperature and stirred for an additional 1 h. When
judged to be complete, the reaction mixture was poured into a
separatory funnel containing H2O (800 mL). The organic layer
was separated, washed with brine, and then dried over MgSO4.
After solvent removal, a yellow solid was obtained, which was
recrystallized from methanol to afford 20 as a yellow solid (54.2
g, 59%). 1H NMR (400 MHz, DMSO-d6) δ 8.06 (m, 2H), 7.92
(d, J ) 8 Hz, 1H), 7.68 (t, J ) 8 Hz, 1H), 7.58 (dd, J ) 4, 8 Hz,
1H), 7.41 (d, J ) 4 Hz, 1H), 7.19 (d, J ) 8 Hz, 1H), 3.61 (s,
3H).
1
drying to provide 8 as a white solid (71.25 g, 46%). H NMR
(DMSO-d6, 400 MHz) δ 9.41 (s, 1H), 8.20 (t, J ) 2 Hz, 1H),
8.09 (td, J ) 2, 8 Hz, 2H), 7.71 (t, J ) 8 Hz, 1H), 7.65 (m, 3H),
7.59 (dd, J ) 2, 8 Hz, 1H), 7.51 (d, J ) 3 Hz, 1H), 7.26 (s, 2
H), 7.24 (d, J ) 9 Hz, 1H), 4.80 (s, 2H), 2.17 (s, 3H). Anal.
Calcd for C23H18ClN3O5S: C, 57.08; H, 3.75; N, 8.68. Found:
C, 57.23; H, 3.75; N, 8.68.
3-(5-Ch lor o-2-h yd r oxyben zoyl)ben zon itr ile (21). Into a
round-bottom flask equipped with an overhead stirrer and N2
on demand were placed 20 (100 g, 0.37 mmol) and CH2Cl2 (1
L). The solution was cooled to -78 °C and boron tribromide
(100 g, 0.4 mol) was added dropwise over 30 min. The resulting
dark mixture was allowed to warm to room temperature and
stirred for an additional 2 h. The mixture was carefully poured
over ice, and the two-phase mixture was stirred for 30 min.
The organic layer was collected and dried over MgSO4. After
solvent removal subsequent drying in vacuo for 2 days, 21 was
obtained as a yellow solid (92 g, 97%), which was used without
Sod iu m 3-(3-Met h yl-4-n it r op h en oxy)p r op a n e-1-su l-
fon a te (28). To a round-bottom flask equipped with an
overhead stirrer, an addition funnel, and N2 on demand were
placed NaH (7.8 g of 60 wt % in mineral oil, 0.20 mol) and
anhydrous THF (300 mL). The mixture was cooled to 0 °C,
and 2-methyl-3-nitrophenol (30 g, 0.20 mol) was added drop-
wise as a solution in THF (100 mL). The reaction was then
allowed to warm to room temperature, heated to 40 °C for 15
min, and then allowed to cool to room temperature. 1,3-
Propane sultone (25.6 g, 0.21 mol) in THF (100 mL) was added
dropwise, and the reaction was heated to reflux for 4-6 h.
When judged to be complete, the reaction mixture was filtered,
and the resulting solid was washed with absol EtOH and Et2O,
and dried in a vacuum oven. A solid precipitated out of the
mother liquor that was filtered, washed with absol EtOH and
Et2O, and dried in a vacuum oven to afford a combined yield
1
any further purification. H NMR (CDCl3, 400 MHz) δ 10.41
(s, 1H), 8.05 (m, 1H), 7.95 (d, J ) 8 Hz, 1H), 7.68 (t, J ) 8 Hz,
1H), 7.43 (dd, J ) 4, 9 Hz, 1H), 7.34 (m, 1H), 6.94 (d, J ) 8
Hz, 1 H).
E t h yl [4-Ch lor o-2-(3-cya n ob en zoyl)p h en oxy]a cet a t e
(22). Into a three-neck round-bottom flask equipped with an
overhead stirrer, reflux condenser, and N2 on demand were
placed 21 (91 g, 0.35 mol), acetone (1 L), K2CO3 (97 g, 0.7 mol),
and ethyl bromoacetate (62 g, 0.37 mol). The resulting mixture
was heated to reflux for 2.5 h, after which it was allowed to
cool to room temperature and was poured into a separatory
funnel containing EtOAc and H2O. The organic layer was
collected and was dried over MgSO4. After solvent removal and
drying in vacuo overnight, 22 (149 g, crude) was obtained as
an oil, which was used in the following reaction without further
purification. 1H NMR (400 MHz, DMSO-d6) δ 8.04 (m, 2H),
8.00 (d, J ) 8 Hz, 1H), 7.67 (t, J ) 8 Hz, 1 H), 7.55 (dd, J )
4, 8 Hz, 1 H), 7.45 (d, J ) 4 Hz, 1 H), 7.09 (d, J ) 12 Hz, 1H),
4.71 (s, 2H).
1
of 28 as a pale yellow solid (27 g, 46%). H NMR (300 MHz,
DMSO-d6) δ 8.06 (d, J ) 9 Hz, 1H), 7.05 (d, J ) 2.7 Hz, 1H),
6.98 (dd, J ) 2.7, 9.3 Hz, 1H), 4.22 (t, J ) 6.6 Hz, 2H), 2.58
(m, 2H), 2.52 (s, 3H), 2.04 (m, 2H).
3-(3-Meth yl-4-n itr op h en oxy)p r op a n e-1-su lfon yl Ch lo-
r id e (29). To a round-bottom flask equipped with a stir bar,
an addition funnel, and N2 on demand were added 28 (11 g,
0.037 mol) and DMF (250 mL), and the reaction was cooled to
0 °C. Thionyl chloride (8.0 mL, 13.0 g, 0.11 mol) was added
dropwise, and the resulting mixture was allowed to stir at 0
°C for 0.5 h, after which it was allowed to warm to room
temperature and stir for an additional 3 h. When judged to be
complete, the reaction mixture was poured into a beaker of

Benzophenone Reverse Transcriptase Inhibitors of HIV-1
J ournal of Medicinal Chemistry, 2004, Vol. 47, No. 5 1181
ice, and the resulting white precipitate was filtered and placed
in a vacuum oven to afford 29 as a white solid (8.7 g, 80%). 1H
NMR (300 MHz, DMSO-d6) δ 8.06 (d, J ) 9 Hz, 1H), 7.05 (d,
J ) 2.7 Hz, 1H), 6.98 (dd, J ) 2.7, 9.3 Hz, 1H), 4.22 (t, J ) 6.3
Hz, 2H), 2.61 (m, 2H), 2.57 (s, 3H), 2.04 (m, 2H).
3-(3-Met h yl-4-n it r op h en oxy)p r op a n e-1-su lfon a m id e
(30). To a round-bottom flask equipped with a stir bar, an
addition funnel, and N2 on demand were added NH4OH (10
mL) and THF (20 mL), and the reaction was cooled to 0 °C.
Sulfonyl chloride 29 (2 g, 6.8 mmol) in THF (20 mL) was added
dropwise, and the reaction was allowed to stir at 0 °C for 15
min, after which the reaction was poured into a beaker of ice
and extracted with EtOAc. The organic layer was collected,
washed with H2O, dried over MgSO4, and filtered. After solvent
removal, 30 was obtained as a white solid (1.4 g, 77%). 1H
NMR (300 MHz, DMSO-d6) δ 8.07 (d, J ) 9 Hz, 1H), 7.06 (d,
J ) 2.7 Hz, 1H), 7.00 (dd, J ) 2.7, 9 Hz, 1H), 6.91 (s, 2H),
4.24 (t, J ) 6 Hz, 2H), 3.16 (t, J ) 7.5 Hz, 2H), 2.56 (s, 3H),
2.18 (m, 2H).
where E′ is a mixture of free enzyme, enzyme-nucleotide
complex, enzyme-template primer complex, and enzyme-
nucleotide-template primer complex, I is inhibitor, kon is the
inhibitor on rate constant, koff is the inhibitor off rate constant,
Vmax is the uninhibited reaction rate, and P is product.
If reactions were linear over 40 min, then IC50 values were
determined by fitting
y ) Vmax × IC50 × t/(IC50 + [I])
(1)
to the data where y was the observed fluorescence at time t
(minutes), Vmax was the uninhibited rate (fluorescence min-1),
and [I] was the inhibitor concentration (molar). If the data
indicated that the reaction could not be completely inhibited
by increasing [I], the IC50 value was determined by fitting eq
1 to only the data from reactions containing low [I]. Limited
inhibition was attributed to inhibitor insolubility.
If inhibited reactions were not linear over 40 min, indicating
slow time-dependent inhibition, kinetic constants kon and koff
were determined by nonlinear least-squares fit of the equation
3-(4-Am in o -3-m e t h y lp h e n o x y )p r o p a n e -1-s u lfo n a -
m id e (12). To a plastic-coated reaction vessel, equipped with
a stir bar, were added 30 (0.29 g, 1.1 mmol), absol EtOH (25
mL), and palladium on charcoal (29 mg of 10% Pd/C, 10 wt
%). The vessel was placed on a hydrogenation apparatus at
60 psi for 3 h. When judged to be complete, the reaction was
filtered through a Celite plug, and the EtOH was removed
under reduced pressure to provide 12 (0.25 g, 98%) as a pale
brown solid. 1H NMR (400 MHz, DMSO-d6) δ 6.80 (s, 2H), 6.54
(s, 1H), 6.49 (s, 2H), 4.34 (s, 2H), 3.89 (t, J ) 6 Hz, 2H), 2.58
(m, 2H), 3.05 (m, 2H), 1.99 (m, 5H).
y ) (Vmax × koff/(kon[I] + koff))t) + (Vmaxkon[I]/((kon[I] +
koff)2))(1 - exp(-(kon[I] + koff)t)
N-{4-[3-(Am in osu lfon yl)p r op oxy]-2-m eth ylp h en yl}-2-
{4-c h lo r o -2-[3-flu o r o -5-(t r i flu o r o m e t h y l)b e n z o y l]-
p h en oxy}a ceta m id e (9). 10a (obtained from the reaction of
16 (13 g, 0.035 mol), oxalyl chloride (7.0 mL, 9.8 g, 0.077 mol),
DMF (1 drop), and CH2Cl2 (100 mL) according to the procedure
described above), 12 (7.81 g, 0.032 mol), NaHCO3 (15 g, 0.18
mol), acetone (125 mL), and H2O (10 mL) were used according
to the procedure described for the synthesis of 7. The product
was crystallized from MeOH to afford 9 as a white solid (10.5
g, 50%). 1H NMR (300 MHz, DMSO-d6) δ 9.16 (s, 1H), 8.05 (d,
J ) 8.4 Hz, 1H), 7.90 (m, 2H), 7.71 (dd, J ) 2.7, 9 Hz, 1H),
7.57 (d, J ) 2.7 Hz, 1H), 7.25 (d, J ) 9 Hz, 1H), 7.13 (d, J )
9 Hz, 1H), 6.88 (s, 2H), 6.80 (d, J ) 2.7 Hz, 1H), 6.73 (dd, J )
2.7, 9 Hz, 1H), 4.74 (s, 2H), 4.07 (t, J ) 6 Hz, 2H), 3.13 (m,
2H), 2.13 (m, 2H), 2.03 (s, 3H). MS (ES): 602 (M-H)-, 603
(M+). Anal. Calcd for C26H23N2O6ClF4S: C, 51.79; H, 3.84; N,
4.65. Found: C, 51.91; H, 3.88; N, 4.66.
where y, Vmax, and I were defined as above, koff was the off
rate constant (min-1), and kon was the on rate constant (M-1
min-1). IC50 was determined by
IC50 ) koff/kon (M)
Again, if the data indicated that the reaction could not be
completely inhibited by increasing [I], the IC50 value was
determined by fitting eq 2 to only the data from reactions
containing low [I].
RT En zym e Assa y: Con tin u ou s Tim e-Resolved F lu o-
r escen ce. Reactions contained 100 nM Cy5-dUTP, 40 nM Eu-
labeled template primer, 1 nM purified recombinant RT, 47
mM Tris-HCl, 75 mM KCl, 9.3 mM MgCl2, 0.003% NP40, 9.3
mM dithiothreitol (DTT), and 2% dimethyl sulfoxide (DMSO).
Test compound or control solvent (15 µL) was added to each
well containing 25 µL of substrate solution. The assay was
initiated by adding 10 µL of diluted RT to each well using a
RapidPlate 96-well pipetting station. Incorporation of Cy5-
dUTP into the Eu-labeled template primer was monitored over
40 min by time-resolved fluorescence with a Victor 1420
Multilabel Counter (Wallac). Data reduction was performed
with SigmaPlot (J andel Scientific, Corte Madera, CA).
RT En zym e Assa y: Con tin u ou s Tim e-Resolved F lu o-
r escen ce. Reactions contained 100 nM Cy5-dUTP, 40 nM Eu-
labeled template primer, 1 nM purified recombinant RT, 47
mM Tris-HCl, 75 mM KCl, 9.3 mM MgCl2, 0.003% NP40, 9.3
mM dithiothreitol (DTT), and 2% dimethyl sulfoxide (DMSO).
Test compound or control solvent (15 µL) was added to each
well containing 25 µL of substrate solution. Wells in column
12 contained substrate solution and control solvent without
inhibitor and served as uninhibited controls. The assay was
initiated by adding 10 µL of diluted RT to each well using a
RapidPlate 96-well pipetting station. Incorporation of Cy5-
dUTP into the Eu-labeled template primer was monitored over
40 min by time-resolved fluorescence with a Victor 1420
Multilabel Counter (Wallac). Refer to RR1999/0040/00 for
additional details regarding materials and data analysis.
GW678248X and GW695634A were each tested over a final
concentration range of 0.002 to 2.0 µM, and efavirenz was
tested over a final concentration range of either 0.001 to 1.0
µM or 0.002 to 2.0 µM.
Ack n ow led gm en t. The authors would like to ex-
press their profound appreciation to Thymista (Misty)
Burnett for her help in reviewing the manuscript,
particularly the pharmacokinetic data.
Refer en ces
(1) Palella, F. J .; Delaney, K. M.; Moorman, A. C.; Loveless, M. O.;
Fuhrer, J .; Satten, G. A.; Aschman, D. J .; Holmberg, S. D.for
The HIV Outpatient Study Investigators. Declining morbidity
and mortality among patients with advanced human immuno-
deficiency virus infection. N. Engl. J . Med. 1998, 338, 853-860.
(2) Koup, R. A.; Merluzzi, V. J .; Hargrave, J . L.; Adams, J .;
Grozinger, K.; Eckner, R. J .; Sullivan, J . L. Inhibition of human
immunodeficiency virus type 1 (HIV-1) replication by the dipy-
ridodiazepinone BI-RG-587. J . Infect. Dis. 1991, 163, 966-970.
(3) Freimuth, W. W. Delavirdine mesylate, a potent non-nucleoside
HIV-1 reverse transcriptase inhibitor. Adv. Exp. Med. Biol. 1996,
394, 279-289.
IC50 Deter m in a tion s w ith P u r ified RT En zym es: Con -
tin u ou s Tim e-Resolved F lu or escen ce Assa y. All data
reduction was done with SigmaPlot (J andel Scientific, Corte
Madera, CA). Background fluorescence was subtracted from
all fluorescence readings. Data analyses were based on the
following scheme:

1182 J ournal of Medicinal Chemistry, 2004, Vol. 47, No. 5
Chan et al.
(4) Young, S. D.; Britcher, S. F.; Tran, L. O.; Payne, L. S.; Lumma,
W. C.; Lyle, T. A.; Huff, J . R.; Anderson, P. S.; Olsen, D. B.;
Carroll, S. S.; Pettibone, D. J .; O’Brien, J . A.; Ball, R. G.; Balani,
S. K.; Lin, J . H.; Chen, I.-W.; Schleif, W. A.; Sardana, V. V.; Long,
W. J .; Byrnes, V. W.; Emini, E. A. L-743,726 (DMP-266): a Novel
Highly Potent Nonnucleoside Inhibitor of the Human Immuno-
deficiency Virus Type 1 Reverse Transcriptase. Antimicrob.
Agents Chemother. 1995, 39, 2602-2605.
(5) Esnouf, R.; Ren, J .; Ross, C.; J ones, Y.; Stammers, D.; Stuart,
D. Mechanism of inhibition of reverse transcriptase by non-
nucleoside inhibitors. Nat. Struct. Biol. 1995, 2, 303-308.
(6) Montaner, J . S. G.; Reiss, P.; Cooper, D.; Vella, S.; Harris, M.;
Conway, B.; Wainberg, M. A.; Smith, D.; Robinson, P.; Hall, D.;
Myers, M.; Lange, J . M. A. for the INCAS Study Group. A
Randomized, Double-blind Trial Comparing Combinations of
Nevirapine, Didanosine, and Zidovudine for HIV-Infected Pa-
tients The INCAS Trial. J AMA 1998, 279, 930-937.
(7) Staszewski, S.; Morales-Ramirez, J .; Tashima, K. T.; Rachlis,
A.; Skiest, D.; Stanford, J .; Stryker, R.; J ohnson, P.; Labriola,
D. F.; Farina, D.; Manion, D. J .; Ruiz, N. M. Efavirenz plus
zidovudine and lamivudine, efavirenz plus indinavir, and indi-
navir plus zidovudine and lamivudine in the treatment of HIV-1
infection in adults. N. Engl. J . Med. 1999, 341, 1865-1873.
(8) Wyatt, P. G.; Bethell, R. C.; Cammack, N.; Charon, D.; Dodie,
N.; Dumaitre, B.; Evans, D. N.; Green, D. V. S.; Hopewell, P. L.;
Humber, D. C.; Lamont, R. B.; Orr, D. C.; Plested, S. J .; Ryan,
D. M.; Sollis, S. L.; Storer, R.; Weingarten, G. G. Benzophenone
Derivatives: A Novel Series of Potent and Selective Inhibitors
Short, S. A.; Weaver, K. W.; Ott, R. J .; Ren, J .; Hopkins, A.;
Stuart, D. I.; Stammers, D. K. 2-Amino-6-arylsulfonylbenzoni-
triles as Non-nucleoside Reverse Transcriptase Inhibitors of
HIV-1. J . Med. Chem. 2001, 44, 1866-1882.
(13) See also: Chan, J .; Ferris, R.; Roberts, G.; Short, S.; Weaver,
K.; Hazen, R.; Creech, K.; St Clair, M.; Dornsife, R.; Freeman,
G.; Tidwell, J .; Romines, K.; Schaller, L.; Cowan, J .; Boone, L.
In vitro Characterization of Novel Benzophenone Non-Nonucleo-
side Reverse Transcriptase Inhibitors. Presented at the 10th
Conference on Retroviruses and Opportunistic Infections, Bos-
ton, MA., Feb 10-14, 2003, oral presentation no. 6.
(14) Kellam, P.; Larde, r B. Recombinant Virus Assay: A Rapid,
Phenotypic Assay for Assessment of Drug Susceptibility of
Human Immunodeficiency Virus Type 1 Isolates. Antimicrob.
Agents Chemother. 1994, 38, 23-30.
(15) Miller, V.; V.; de Bethune, M. P.; Kober, A.; Sturmer, M.;
Hertogs, K.; Pauwels, R.; Stoffels, P.; Staszewski, S. Patterns
of resistance and cross-resistance to human immunodeficiency
virus type 1 reverse transcriptase inhibitors in patients treated
with the non-nucleoside reverse transcriptase inhibitor loviride.
Antimicrob. Agents Chemother. 1998, 42, 3123-3129.
(16) Havlir, D. V.; Eastman, S.; Gamst, A.; Richman, D. D. Nevirap-
ine-resistant human immunodeficiency virus: kinetics of rep-
lication and estimated prevalence in untreated patients. J . Virol.
1996, 70, 7894-7899.
(17) Maga, G.; Amacker, M.; Ruel, N.; Hubscher, U.; Spadari, S.
Resistance to Nevirapine of HIV-1 Reverse Transcriptase Mu-
tants: Loss of Stabilizing Interactions and Thermodynamic or
Steric Barriers are Induced by Different Single Amino Acid
Substitutions. J . Mol. Biol. 1997, 274, 738-747.
(18) Demeter, L. M.: Shafer, R. W.; Meehan, P. M.; Holden-Wiltse,
J .; Fischl, M. A.; Freimuth, W. W.; Para, M. F.; Reichman, R. C.
Delavirdine Susceptibilities and Associated Reverse Tran-
scriptase Mutations in Human Immunodeficiency Virus Type 1
of Human Immunodeficiency Virus Type
1 Reverse Tran-
scriptase. J . Med. Chem. 1995, 38, 1657-1665.
(9) Stammers, D. K.; et al. Details of the crystallographic work will
be published in due course.
(10) J ust, C. In Adv. Org. Chem: Methods and Results; Bohme, H.,
Viehe, H., Eds.; Wiley-Interscience: New York, 1976, 9, 225.
(11) Ettel, V.; Hebky, J . The Preparation of Substances of the
o-Aminoazotoluene Type and Their Derivatives Substituted in
the Amino Group (I). Collect. Czech. Chem. Commun. 1948, 13,
161-176.
(12) For experimental details, see: Chan, J . H.; Hong, J . S.; Hunter,
R. N., III; Orr, G. F.; Cowan, J . R.; Sherman, D. B.; Sparks, S.
M.; Reitter, B. E.; Andrews, C. W., III; Hazen, R. J .; St Clair,
M.; Boone, L. R.; Ferris, R. G.; Creech, K. L.; Roberts, G. B.;
Isolates from Patients in
a Phase I/II Trial of Delavirdine
Monotherapy (ACTG 260). Antimicrob. Agents Chemother. 2000,
44, 794-797.
(19) Schinazi, R. F.; Larder, B. A.; Mellors, J . W. Mutations in
retroviral genes associated with drug resistance: 2000-2001
update. Int. Antiviral News 2000, 8, 65-91.
J M030255Y