Inhibition of clinically relevant mutant variants of HIV-1 by quinazolinone non-nucleoside reverse transcriptase inhibitors

Article abstract of DOI:10.1021/jm990580e

A series of 4-alkenyl and 4-alkynyl-3,4-dihydro-4-(trifluoromethyl)-2- (1H)-quinazolinones were found to be potent non-nucleoside reverse transcriptase inhibitors (NNRTIs) of human immunodeficiency virus type-1 (HIV-1). The 4-alkenyl-3,4-dihydro-4-(triflu

Full text of DOI:10.1021/jm990580e

J . Med. Chem. 2000, 43, 2019-2030
2019
In h ibition of Clin ica lly Releva n t Mu ta n t Va r ia n ts of HIV-1 by Qu in a zolin on e
Non -Nu cleosid e Rever se Tr a n scr ip ta se In h ibitor s
J effrey W. Corbett,* Soo S. Ko, J ames D. Rodgers, Lisa A. Gearhart, Nicholas A. Magnus, Lee T. Bacheler,
Sharon Diamond, Susan J effrey, Ronald M. Klabe, Beverly C. Cordova, Sena Garber, Kelly Logue,
George L. Trainor, Paul S. Anderson, and Susan K. Erickson-Viitanen
DuPont Pharmaceuticals Company, Experimental Station, Wilmington, Delaware 19880-0500
Received November 22, 1999
A series of 4-alkenyl and 4-alkynyl-3,4-dihydro-4-(trifluoromethyl)-2-(1H)-quinazolinones were
found to be potent non-nucleoside reverse transcriptase inhibitors (NNRTIs) of human
immunodeficiency virus type-1 (HIV-1). The 4-alkenyl-3,4-dihydro-4-(trifluoromethyl)-2-(1H)-
quinazolinones DPC 082 and DPC 083 and the 4-alkynyl-3,4-dihydro-4-(trifluoromethyl)-2-
(1H)-quinazolinones DPC 961 and DPC 963 were found to exhibit low nanomolar potency toward
wild-type RF virus (IC90 ) 2.0, 2.1, 2.0, and 1.3 nM, respectively) and various single and many
multiple amino acid substituted HIV-1 mutant viruses. The increased potency is combined
with favorable plasma serum protein binding as demonstrated by improvements in the percent
free drug in human plasma when compared to efavirenz: 3.0%, 2.0%, 1.5%, 2.8%, and 0.2-
0.5% for DPC 082, DPC 083, DPC 961, DPC 963, and efavirenz, respectively.
In tr od u ction
The fact that human immunodeficiency virus (HIV)
infection is a global health problem is apparent from
the estimated emergence of 16 000 new cases daily.1-3
There is substantial evidence to suggest that immediate
therapy be considered for persons with acute HIV
infection to effectively inhibit the replication of HIV
virus.4 Unfortunately, mutant virus forms appear in
clinical situations where there is continued replication
of HIV virus in the presence of suboptimal levels of
drug(s) and through acute HIV infection with drug
resistant strains.5 These phenomena require the devel-
opment of new therapeutics capable of suppressing the
viral replication of these mutant virus forms.
One therapeutic target in the treatment of AIDS is
the inhibition of HIV reverse transcriptase (RT), the
enzyme responsible for the formation of proviral DNA
from viral RNA.6 The inhibition of HIV RT results in
DNA chain termination, a decrease in viral replication,
and a concomitant decrease in viremia. The first gen-
eration of therapeutics designed to inhibit viral RT were
nucleoside substrate analogues, which bind to the ATP-
binding pocket and act as substrate decoys and chain
terminators. Clinical evidence has demonstrated limited
long-term efficacy for these agents in certain combina-
tions, due to the appearance of drug-resistant mutant
viruses and because of hematological toxicities frequent
with this class of drug.
F igu r e 1. Structures of marketed non-nucleoside reverse
transcriptase inhibitors.
resistant virus with greatly decreased susceptibility to
the particular NNRTI has been observed. Although
specific mutations unique to individual NNRTIs (e.g.,
P236L for delavirdine, Y181C for nevirapine or delavir-
dine) have been documented in vitro or in genotyping
data, the RT mutation at amino acid lysine 103 to
asparagine is frequently observed in patients failing
therapy, either alone or in combination with additional
mutations.10 This has led to the designation of K103N
as a “pan-class resistance mutation”.
Efavirenz is an NNRTI with nanomolar potency,
substantial plasma protein binding, and pharmacoki-
netics allowing once-daily dosing which has demon-
strated significant clinical activity, both in combination
with protease inhibitors or in a protease-sparing regi-
men consisting of efavirenz plus two nucleoside RT
inhibitors.11 In clinical trials in which efavirenz is
combined with other highly active antiretroviral agents,
viral load response is at least as significant and durable
as any other HIV compound tested to date.11,12 Although
the majority of patients on efavirenz-containing regi-
A second class of RT inhibitors are the non-nucleoside
reverse transcriptase inhibitors (NNRTIs), which bind
to an allosteric site in the HIV-1 RT enzyme.7 Three
NNRTIs have been approved for the treatment of HIV-1
infection: nevirapine, delavirdine, and, most recently,
efavirenz (Figure 1).
In clinical trials with NNRTIs as monotherapy,8 and
in in vitro selection experiments,9 rapid emergence of
* To whom correspondence should be addressed. Tel: 302-695-4823.
Fax: 302-695-9673. E-mail: jeffrey.w.corbett@dupontpharma.com.
10.1021/jm990580e CCC: $19.00 © 2000 American Chemical Society
Published on Web 04/20/2000

2020 J ournal of Medicinal Chemistry, 2000, Vol. 43, No. 10
Sch em e 1. Synthesis of 8e, 8h , and 8ia
Corbett et al.
Sch em e 2. Synthesis of 4-Alkynyl-3,4-dihydro-4-
trifluoromethylquinazolin-2(1H)-onesa
a
(a) (i) TMSNCO, THF, (ii) TBAF/THF; (b) KOCN, AcOH/H2O;
(c) toluene or xylenes, reflux, 4 Å molecular sieves; (d) LitR,
BF3‚OEt2, THF.
chlorosuccinimide in hot DMF to give the 5-fluoro-6-
chloro derivatized aniline 4. Metalation of 4 with
n-butyllithium at -78 °C followed by quenching the
anion with ethyl trifluoroacetate gave 5. Hydrolysis of
the pivaloyl group afforded the desired aniline 8h .
Similar to the synthesis of 8e, 3,4-dichloroaniline was
functionalized as the N-Boc derivative 6 and metalated
using a mixture of tert-butyllithium and N, N, N′, N′-
tetramethylethylenediamine (TMEDA) in tetrahydro-
furan (THF) at -78 °C, and the resultant anion was
quenched with ethyl trifluoroacetate to afford 7. Re-
moval of the Boc group from 7 gave aniline 8i.
Treatment of amino ketones 8a -i with either trim-
ethylsilylisocyanate18 followed by tetrabutylammonium
fluoride (TBAF) or potassium cyanate in aqueous acetic
acid delivered aminols 9a -i (Scheme 2). Heating 9a -i
with 4 Å molecular sieves in either toluene or xylenes
at reflux effected the desired dehydration to afford the
trifluoromethyl ketimines 10a -i. Aminols containing a
5-halogen substituent required higher temperatures to
effect dehydration and were therefore dehydrated using
xylenes as the solvent. Ketimines 10a -i were alkylated
with a THF solution of lithiated alkynes in the presence
of a catalytic amount of boron trifluoride etherate (BF3‚
OEt2) to give the desired quinazolinones. It was found
necessary to use a Lewis acid since the rate of lithium
acetylide addition to ketimine 10 in the absence of BF3‚
OEt2 was sluggish, while use of greater than 0.5 equiv
of BF3‚OEt2 resulted in reduced yields of the desired
products.
The ability of the racemic quinazolinones to inhibit
HIV-1 RT in an in vitro enzyme assay (IC50 data)3 and
to inhibit wild-type RF strain of HIV-119 (IC90 data) is
represented in Table 1. To get an estimate of the extent
of protein binding, and its subsequent impact on anti-
viral potency, a rapid assay to determine the effects of
plasma protein binding was devised. The addition of
heat inactivated human serum at concentrations in
excess of about 25% is cytotoxic, precluding a direct
assessment. However, since albumin and acid glycopro-
tein comprise the major proteins of serum, the impact
of these two components was examined at concentra-
tions found in human serum. In the “protein binding
shift assay”, the antiviral potency is determined by
measurement of viral RNA in standard tissue culture
a
(a) NaHMDS, Boc2O, THF; (b) (i) t-BuLi, TMEDA, THF, (ii)
CF3CO2Et; (c) 4 N HCl in dioxane; (d) NCS, DMF, 80 °C; (e) (i)
n-BuLi, THF, (ii) CF3CO2Et; (f) 6 N HCl, DME, reflux.
mens have shown a sustained antiviral response, pa-
tients whose viral load levels have rebounded after an
initial response to drug have the K103N mutation in
over 90% of sequences examined.12 Following the ap-
pearance of virus with the K103N mutation, viruses
with multiple mutations arise more slowly. For instance,
the double mutations K103N+V108I or K103N+P225H
are observed in a large number of samples approxi-
mately 4 months after initial viral load rebound.12
The highly resistant virus with the double mutation
K103N+L100I is much less prevalent. Considering the
significant antiviral benefit apparent from ongoing
clinical trials with efavirenz, development of additional
NNRTIs which retain similar ease of administration and
safety profiles, but with superior overall profiles against
mutant viruses such as K103N, K103N+V108I, and
K103N+P225H, should provide even more powerful
drugs to serve as cornerstones of combination regimens
and as components of salvage therapy when other
treatment modalities have failed.
The structure-activity relationship leading to the
identification of four new NNRTI analogues is described
wherein we simultaneously considered intrinsic potency,
plasma protein binding, and pharmacokinetics during
the iterative synthesis process. We have identified a
cohort of four related analogues that combine improved
potency against mutant HIV variants with substantial
oral bioavailability, long plasma half-life, and moderate
plasma protein binding.
Ch em istr y a n d Biologica l Resu lts
Amino ketones 8a -h (Scheme 2) were prepared as
previously reported,13,14 with the exception of 8e, 8h ,
and 8i, which were prepared as described in Scheme 1.
N-Boc-protected 3-chloro-4-fluoro aniline 1, prepared via
Kelly’s procedure using sodium hexamethyldisilazide
(NaHMDS),15 was metalated under conditions previ-
ously described in the literature16 and quenched with
ethyl trifluoroacetate to give 2. Removal of the N-Boc
protecting group delivered amino ketone 8e. Pivaloy-
lated 3-fluoroaniline 317 was chlorinated using N-

Inhibition of Mutant Variants of HIV-1
J ournal of Medicinal Chemistry, 2000, Vol. 43, No. 10 2021
Ta ble 1. In Vitro Biological Activity of 4-Alkynyl, 4-Trifluoromethyl-3,4-dihydro-2(1H)-quinazolinones
IC90 (nM)
compd
X
R
enzyme IC50 (nM)3
antiviral activity19
PB adj wild-type IC90 (nM)
PB fold shift
25
11
22
12
13
20
16
28
27
15
efavirenz
17
31
18
30
14
24
36
33
35
29
26
34
23
19
21
5,6-F2
5-F
5-Cl,6-F
5-Cl
5,6-F2
5,6-F2
6-F
5,6-F2
6-F
ethyl
74 ( 27
62 ( 13
1.5
1.4
3.0
2.5
2.1
2.1 ( 1.4
2.0
2.0
2.5
2.7
1.7 ( 0.5
2.9
5
4.8
2.3
2.7 ( 0.6
3.8
3.2
6.2
6.6
3.4
3.3
7.1
2.6
8.0
3.0 ( 0.2
50 ( 10
8.1
10
14
15
18
19
21
24
24
25
27
28
29
33
40
41
41
42
42
43
66
79
83
86
86
88
6.9
10
5
7
9
cyclopropyl
isopropyl
cyclopropyl
cyclopropyl
isopropyl
cyclopropyl
2-pyridyl
ethyl
cyclopropyl
see Figure 1
cyclopropyl
2-pyridyl
cyclopropyl
2-pyridyl
cyclopropyl
isopropyl
phenyl
phenyl
phenyl
2-pyridyl
ethyl
phenyl
isopropyl
cyclopropyl
isopropyl
see Figure 1
2-pyridyl
see Figure 1
78 ( 25
72 ( 15
74 ( 35
91 ( 13
9.8
12
12
10
10
16.5
10
7
8.4
18
15
11
13
7
10
23
25
12
33
11
30
2
50 ( 4
68 ( 17
54 ( 9
5-Cl,6-F
59 ( 12
47 ( 25
6-MeO
6-F
5-F,6-Cl
5-Cl,6-F
6-Cl
6-MeO
6-MeO
5,6-F2
6-F
6-Cl
6-Cl
6-Cl
6-F
124 ( 90
126 ( 30
102 ( 67
80 ( 15
111 ( 34
401 ( 182
219 ( 34
181 ( 83
143 ( 30
129 ( 36
110 ( 61
277 ( 94
39 ( 8
166 ( 38
281 ( 105
4848 ( 1739
237 ( 99
422 ( 92
5,6-Cl2
6-Cl
90
nevirapine
32
delavirdine
100
138
1406
6-MeO
17
38
37 ( 9
medium or in tissue culture medium to which 45 mg/
mL human serum albumin and 1 mg/mL alpha-1 acid
glycoprotein have been added. The ratio of the measured
90% inhibitory concentrations were then expressed as
a fold increase in measured IC90 (PB fold shift).
As seen in Table 1, except for 32, all compounds tested
were more potent inhibitors of wild-type HIV-1 than
either nevirapine or delavirdine and most analogues had
wild-type antiviral potency similar to that of efavirenz,
with compounds 11 and 25 appearing potentially more
potent (racemates contain only 50% of the active enan-
tiomer). Taking into account the estimated effect of
human plasma protein binding by multiplying the
observed IC90 value by the PB fold shift gave the protein
binding adjusted (PB Adj) IC90 data. When this was
done, it became evident that several analogues appeared
more potent than efavirenz. It was also apparent that
incorporation of a 5-halo substitituent, either in the
presence or the absence of a 6-halo substituent, con-
ferred beneficial activity as exemplified by the six most
active compounds in Table 1. Small groups on the
alkyne, such as the ethyl analogue 25, appear to be
favored over larger groups, such as phenyl analogue
33.20 Two 2-pyridyl containing compounds, 28 and 31,
are also very potent, but less so than their corresponding
cyclopropylalkynyl (13 and 16, respectively) and butynyl
(25 and 27, respectively) analogues. Comparing similar
pairs of analogues, 5,6-difluoro substituents confer
improvements in potency compared to 6-chloro ana-
logues.
frequently observed alone, or in combination with other
mutations in nevirapine and delavirdine failures.10,12
The L100I mutation was selected by efavirenz through
in vitro selection experiments.19 The compounds in
Table 2 are ranked by their potency against the K103N
mutant virus, adjusting for the effects of protein binding
using the PB shift assay. The potency of some of the
new analogues against the K103N mutant virus was
significantly increased compared to that of efavirenz.
When the estimated effects of protein binding were
taken into account, the superior potency of the new
analogues became even more evident. It was found that
compounds having a 5-halogen substitution, with or
without a halogen in the 6-position, showed the most
potent activity against the K103N mutant. In particular,
the racemate 22 exhibited exceptional activity toward
inhibiting the K103N containing virus, as exhibited by
its 74 nM protein binding adjusted IC90. The improve-
ment of racemic 22 toward the protein binding adjusted
K103N IC90 value over delavirdine, nevirapine, and
efavirenz is striking: 510-, 140-, and 14-fold improve-
ment, respectively.
Prior to the discovery of 22, several of the best
quinazolinones, 13, 14, and 20, were synthesized on
gram scale and the enantiomers separated by chiral
HPLC. The active isomers of these compounds are DPC
961, DPC 963, and 37 (Figure 2). The absolute stereo-
chemistry of DPC 961 was determined from a single-
crystal X-ray, while the absolute stereochemistry of DPC
963 and 37 was inferred from the data obtained in the
enzyme and whole cell assays, with the undesired
enantiomers exhibiting virtually no activity (Table 3).
Upon oral dosage of a mixture of 37, DPC 961, and
DPC 963 in rhesus monkeys, only DPC 961 and DPC
963 were found to be present in micromolar concentra-
tions, whereas 37 was undetectable in plasma. Studies
The ability of racemic quinazolinones to inhibit rep-
lication of mutant viruses possessing the amino acid
substitution K103N or L100I is listed in Table 2. The
clinically significant HIV single mutant K103N is the
most prevalent mutation observed in vivo in patients
who have failed efavirenz-containing regimens and is

2022 J ournal of Medicinal Chemistry, 2000, Vol. 43, No. 10
Corbett et al.
Ta ble 2. Resistance Profiles of 4-Alkynyl, 4-Trifluoromethyl-3,4-dihydro-2(1H)-quinazolinones
IC90 (nM)
compd
X
R
antiviral activity K103N
antiviral activity L100I
PB adj antiviral activity toward K103N
22
25
13
20
18
15
19
14
17
12
16
24
21
27
26
23
11
efavirenz
30
28
33
34
31
35
36
5-Cl,6-F
isopropyl
ethyl
15
14
13
14
18
18
18
22
40
63
48
56
22
71
26
27
89
13
18
12
74
93
119
139
151
178
196
336
396
441
566
599
653
710
826
891
917
1056
1307
1308
1337
3000
3140
3220
3594
3728
5881
10200
38000
5,6-F2
5,6-F2
5,6-F2
e
cyclopropyl
isopropyl
cyclopropyl
cyclopropyl
cyclopropyl
cyclopropyl
cyclopropyl
cyclopropyl
cyclopropyl
isopropyl
isopropyl
ethyl
10
5-F,6-Cl
5-Cl,6-F
5,6-Cl2
6-Cl
6-MeO
5-Cl
6-F
6-MeO
6-Cl
6-F
6-Cl
6-F
5-F
NDa
16
ND
18
46
70
29
28
28
74
ND
17
ethyl
isopropyl
cyclopropyl
108
77 ( 26
44
64 ( 24
73
109
191
250
483
322
283
160
338
5100 ( 830
1000 ( 270
5-Cl,6-F
5,6-F2
5,6-F2
6-Cl
6-F
6-F
6-MeO
6-Cl
6-MeO
2-pyridyl
2-pyridyl
phenyl
phenyl
2-pyridyl
phenyl
phenyl
2-pyridyl
2-pyridyl
37
256
365
255
677
462
64
98
ND
ND
29
32
nevirapine
delavirdine
a
ND ) not determined.
resolution of other compounds possessing a metaboli-
cally labile iso-propyl substituted alkyne, such as is
found in compound 22, and evaluation of the single
enantiomer in the assay systems described in Tables 4
and 5 would not lead to an advancement of our ultimate
goal: identifying compounds which possess not only
excellent virologic profiles but have physical properties
consistent with once-daily dosing in humans.
With the favorable pharmacokinetic results obtained
with DPC 961 and DPC 963, we turned our attention
to trying to obtain compounds which might possess
better overall qualities. It was known from previous
SAR for efavirenz that olefin analogues had a slightly
improved profile.20 Therefore, the olefin analogues were
prepared by lithium aluminum hydride reduction of
DPC 961 and DPC 963 to afford DPC 083 and DPC 082,
respectively (Scheme 3). 1,2-Dichlorobenzene was used
in order to suppress dehalogenation of the aromatic
rings during the reduction.
F igu r e 2. Absolute stereochemistry of 37, DPC 961, and DPC
963.
Ta ble 3. Activity of Resolved Quinazolinones
IC90 (nM)
Table 4 compares the virologic profile and protein
binding properties of DPC 961, DPC 963, DPC 082, and
DPC 083 to that of efavirenz using laboratory strains
and clinical isolates of HIV-1 and detection by several
different methods. Like efavirenz, DPC 961, DPC 963,
DPC 082, and DPC 083 are potent in the nanomolar
range against both laboratory and clinical isolates,
maintain that potency against zidovudine resistant
isolates, and are inactive against HIV-2. Within the
standard deviations of the assays, the four new ana-
logues are equal in measured potency to efavirenz.
antiviral activity
K103N
antiviral activity
wild-type
enzyme
IC50 (nM)
compd
37
38
DPC 961
39
9
1.6
229
2.0 ( 0.7
34000
1.3 ( 0.6
101
15 ( 8
1519 ( 49
31 ( 8
267
18 ( 5
6600
NDa
10 ( 3.2
ND
11 ( 4.8
ND
DPC 963
40
a
ND ) not determined.
indicated that the 3-methylbutynyl substituent present
in 37 was rapidly metabolized by liver homogenate
fractions when compared to efavirenz. The metabolic
liability found with compound 37 precluded its further
evaluation in the other assay systems shown in Tables
4 and 5. Using the same line of reasoning, the chiral
Many drugs bind to plasma proteins, and the effect
of such binding is to decrease the concentration of free
drug available to equilibrate across cell membranes and
interact with the target. For AIDS therapeutics, clinical
failure has been associated with significant and unex-

Inhibition of Mutant Variants of HIV-1
J ournal of Medicinal Chemistry, 2000, Vol. 43, No. 10 2023
Ta ble 4. Antiviral Activity and Protein Binding of Second-Generation NNRTIs
IC90 nM
DPC 082
virus
cells
assay
DPC 961
DPC 963
DPC 083
efavirenz
RF
RF
MT-2
MT-2
PBMC
PBMC
MT-2
MT-2
MT-2
RNA
yield
P24
2.0 ( 0.7
2.7 ( 0.4
5.0 ( 3.5
2.5 ( 0.4
ND
1.3 ( 0.6
2.3 ( 0.8
1.9 ( 0.1
1.6 ( 0.1
1.7
2.0 ( 0.2
2.7 ( 0.2
NDd
ND
2.9
2.1 ( 0.8
1.9 ( 0.9
0.9
1.7 ( 0.5
2.4 ( 0.5
8.5
2.8
2.8
Thai 9466a
A018Cb
Eb
P24
ND
Yield
Yield
RNA
1.3 ( 0.7
>2800
3.7
HIV-2
PB shift
>2800
17
>950
6.9
>2800
3.5
>3000
17
DPC 961
DPC 963
DAC 082
DPC 083
efavirenz
% free in human serumc
% free in tissue culture medium
plasma IC90 for RF virus
1.5%
31%
40 nM
2.8%
37%
18 nM
3.0%
53%
33 nM
2.0%
39%
40 nM
0.2-0.5%
27%
92-220 nM
a
b
Thai 9466 is a wild-type clinical isolate. A018C and E are zidovudine-resistant clinical isolates. The genotype of A018C is unknown
and the genotype of E contains the mutations D67N and K70R. c Data from ref 3. ND ) Not determined.
d
Ta ble 5. Potency of Second-Generation NNRTIs against Mutant HIV-1 Variants
parameter
efavirenz
DPC 961
DPC 963
DPC 082
DPC 083
K103N measured IC90 (nM)
K103N free drug IC90 (nM)
64 ( 24
17
10 ( 3.2
3.1
11 ( 4.8
4.0
21 ( 9.2
11
27 ( 11
11
K103N p la sm a IC90 (n M)
sL100I measured IC90 (nM)
sL100I free drug IC90 (nM)
3400-8100
120 ( 30
33
210
13 ( 7.9
4.0
140
8.0 ( 5.7
3.0
370
5.9 ( 3.8
3.1
550
11 ( 6.8
4.3
sL100I p la sm a IC90 (n M)
6600-15700
2400 ( 420
650
270
190 ( 28
59
110
110 ( 44
41
100
250 ( 34
130
220
320
120
6000
sV179D/L100I/Y181C measured IC90 (nM)
sV179D/L100I/Y181C free drug IC90 (nM)
sV179D/L100I/Y181C p la sm a IC90 (n M)
130000-309500
3900
1460
4300
Sch em e 3. Synthesis of DPC 082 and DPC 083a
plasma is 3-14-fold lower than that of efavirenz,
depending on the value used for efavirenz free fraction.
We have defined the property plasma IC90 as the total
drug concentration needed to achieve 90% suppression
of HIV replication. The plasma IC90 is determined by
dividing the concentration of free drug required for
inhibition of HIV (calculated by adjusting the measured
IC90 values by the tissue culture medium binding) by
the free fraction present in human serum. The plasma
IC90 is thus a calculated parameter based on three
different measured values. In the case of efavirenz, the
high degree of plasma protein binding was characterized
by a number of different assays. The data are expressed
as a range of free drug values for this inhibitor (Sustiva
(efavirenz capsules) Product Information Leaflet). The
plasma IC90 for the RF form of HIV-1 is shown in Table
4. The plasma IC90 for all four analogues is 2-12-fold
less than the range determined for efavirenz, an effect
driven almost exclusively by improvements in plasma
protein binding properties. More importantly, a lower
plasma IC90 indicates that at comparable total plasma
levels, greater inhibition of replication should be ob-
served with the second-generation analogues.
Table 5 shows the measured potency, calculated free
drug potency and plasma IC90 for the second-generation
compounds against mutant HIV-1 variants, including
recombinant K103N, and viruses selected for in tissue
culture after exposure of infected cells to efavirenz. Such
selected viruses are indicated by an “s” prefix and
contain the L100I mutation or the triple mutation
V179D/L100I/Y181C.21
Table 5 indicates that all four second-generation
analogues show improved measured potency against
K103N, sL100I, and the triple substituted virus selected
in tissue culture by exposure to efavirenz. This improve-
ment in measured potency ranges from 2.3-fold (K103N
potency for DPC 083 versus efavirenz) to 22-fold (triple
a
(a) LiAlH4, 1,2-dichlorobenzene, THF.
pected protein binding. The influence of albumin and
acid glycoprotein can be estimated by the increase in
the measured IC90 in the presence of these purified
components in the tissue culture medium. As shown in
Table 4, the PB shift assay indicated that all four
analogues showed some binding by the albumin in the
tissue culture medium, as reflected by an increase in
the measured IC90. Importantly, tissue culture medium
is supplemented with heat-inactivated calf serum to
maintain cell integrity. The shift data suggested that
binding to the albumin in the fetal calf serum might
likely occur. To accurately assess binding to tissue
culture medium and human serum in order to predict
drug levels required for adequate inhibition of replica-
tion, ultrafiltration was used to determine the free
fraction at equilibrium. The percent free drug in tissue
culture medium or human serum is shown in Table 4.
Note that for efavirenz and the new analogues, the PB
shift assay underpredicts the extent of plasma protein
binding measured by physical separation and detection.
To maintain suppression of virus replication, the
concentration of free drug in the plasma must exceed
the free drug concentration required for inhibition of
replication. Table 4 shows that the percentage binding
of the second-generation NNRTIs by proteins in human

2024 J ournal of Medicinal Chemistry, 2000, Vol. 43, No. 10
Corbett et al.
mutant potency for DPC 963 versus efavirenz). Because
of decreased binding by human serum proteins, the
plasma IC90 values are markedly improved for the
second-generation compounds. Using the most favorable
plasma IC90 values for efavirenz, the second-generation
compounds show at least 6-, 24-, and 22-fold lower
plasma IC90 values than efavirenz for the K103N,
sL100I, and sV179D/L100I/Y181C triple substituted
viruses, respectively. Provided human plasma levels are
similar to those observed for efavirenz, where 5.6 µM
is the observed trough level at 600 mg qd, any of the
four second-generation compounds could provide suf-
ficient drug at trough for at least 90% suppression of
wild type and K103N- and L100I-containing single and
triple substituted viruses. We have previously reported
that chimpanzee pharmacokinetics are consistent with
once daily dosing and the attainment of high plasma
levels.3 Chimpanzee trough levels normalized to a single
10 mg/kg dose were 12.7 µM for DPC 961, 6.2 µM for
DPC 963, 4.7 µM for DPC 082, and 7.6 µM for DPC 083.
For comparison, the trough level for efavirenz in the
chimpanzee is 2.7 µM. All four compounds are complet-
ing phase I studies in sero-negative volunteers so that
we may identify which compound gives the required
trough levels to cover the target virus populations.
Exp er im en ta l Section
Ch em ica l Meth od s. All procedures were carried out under
argon in oven-dried glassware unless otherwise indicated.
Proton NMR spectra were obtained on VXR or Unity 300 MHz
instruments (Varian Instruments, Palo Alto) with chemical
shifts δ in ppm downfield from TMS as an internal reference
standard. Melting points were determined on a Bu¨chi 535
melting point apparatus and are uncorrected. Elemental
analyses were performed by Quantitative Technologies, Inc.,
Bound Brook, NJ 08805. Mass spectra were measured with a
HP 5988A mass spectrometer with particle beam interface
using NH3 for chemical ionization or a Finnigan MAT 8230
mass spectrometer with NH3-DCI or VG TRIO 2000 for ESI.
High-resolution mass spectra were measured on a VG 70-VSE
instrument with NH3 ionization. Optical rotations were ob-
tained on a Perkin-Elmer 241 polarimeter. Solvents and
reagents were obtained from commercial vendors in the
appropriate grade and used without further purification unless
otherwise indicated.
(3-Ch lor o-4-flu or op h en yl)ca r ba m ic Acid ter t-Bu tyl Es-
ter (1). To a solution of 3-chloro-4-fluoroaniline (10.0 g, 68.7
mmol) in anhydrous THF (69 mL) was slowly added sodium
bis(trimethylsilyl)amide (137 mL of 1.0 M solution in THF).
The mixture was stirred at room temperature for 1.5 h before
addition of a solution of Boc2O (15.0 g, 68.7 mmol) in anhydrous
THF (5 mL). The mixture was aged at room temperature for
3 h, concentrated under reduced pressure, diluted with EtOAc
(200 mL), and washed with 0.5 N HCl (250 mL). The aqueous
phase was back-extracted with EtOAc (100 mL). The combined
organic extracts were dried over MgSO4, filtered, and concen-
trated, to give 16.1 g of crude 1 which was used without further
purification (95% yield): mp 130-132 °C; 1H NMR (300 MHz,
acetone-d6) δ 8.59 (br s, 1H), 7.80 (dd, J ) 6.4, 2.4 Hz, 1H),
7.45-7.39, (m, 1H), 7.22-7.16 (m, 1H), 1.46 (s, 9H).
[3-Ch lor o-4-flu or o-2-(2,2,2-t r iflu r oe t h a n on e )p h e n -
yl]ca r ba m ic Acid ter t-Bu tyl Ester (2). To a solution of
anhydrous THF (15 mL) containing TMEDA (2.37 g, 3.08 mL,
20.4 mmol) at -78 °C was added t-BuLi (12.0 mL of 1.7 M
solution). The mixture was aged at -78 °C for 0.5 h, before
addition of a -78 °C solution of 1 (2.50 g, 10.2 mmol) in
anhydrous THF (20 mL) via cannula over approximately 10
min. The mixture was aged at -78 °C for 2 h and then ethyl
trifluoroacetate (2.90 g, 2.43 mL, 20.4 mmol) was added. The
cooling bath was removed and the mixture was allowed to
warm to room temperature. The mixture was quenched with
saturated aqueous NH4Cl after 2 h and extracted with EtOAc
(150 mL), washed with saturated aqueous NaHCO3 (80 mL)
and aqueous NaCl (80 mL), dried over MgSO4, filtered, and
concentrated. The concentrate was purified by flash chroma-
tography (15% EtOAc/hexanes) to give 1.03 g of 2 as a yellow
solid (30% yield): mp 144 °C; 1H NMR (300 MHz, acetone-d6)
δ 7.83 (dd, J ) 8.8, 4.8 Hz, 1H), 7.32-7.25 (m, 1H), 1.68 (s,
9H); 19F NMR (282 MHz, acetone-d6) δ -77.7 (s, 3F), -117.8
(s, 1F).
Con clu sion s
A series of trifluoromethyl-containing quinazolinones
were synthesized and evaluated for their ability to
inhibit wild-type and various mutant forms of HIV-1.
Quinazolinones were examined since previous work had
shown that potency toward HIV-1 reverse transcriptase
could be achieved with these compounds, although the
previously reported materials had a poor resistance
profile.22 It was felt that an improvement in the overall
resistance profile could be achieved by the incorporation
of a trifluoromethyl group into the molecule, as found
in efavirenz, and by manipulating the alkyne side chain.
We simultaneously considered potency, protein bind-
ing, and pharmacokinetic properties when character-
izing and ranking new analogues. It was found that the
presence of the cyclopropyl acetylene moiety was critical
in order to achieve satisfactory blood plasma levels. An
increase in the overall resistance profile was observed
for compounds possessing a 5,6-dihalogen substitution
pattern when compared to the 5- or 6-monohalogen-
substituted analogues. The improvement in potency of
the 5,6-dihalogen-substituted analogues was due in
large part to less protein binding when compared to
monohalogenated compounds. The overall profile of DPC
961, DPC 963, DPC 082, and DPC 083 suggests strongly
that any of these new analogues could provide superior
coverage of wild type and mutant HIV variants relative
to efavirenz, provided that the pharmacokinetics in
humans are similar to those previously observed for
efavirenz. Considering the powerful antiviral benefit
apparent from ongoing clinical studies with efavirenz,
development of additional NNRTIs that retain similar
ease of administration and safety profile, but with
superior overall profiles against mutant variants, should
provide even more durable drugs to serve as constitu-
ents of combination drug regiments and as components
of salvage therapy when other treatment modalities
have failed.
2,2-Dim eth yl-N-(3-flu or op h en yl)p r op a n a m id e (3) was
prepared according to a literature procedure:17b mp 112.5-
113 °C (lit. mp 100-101 °C17a and 112-114 °C17b).
1-(2-Am in o-6-ch lor o-5-flu or op h en yl)-2,2,2-tr iflu or oet-
h a n on e (8e). A solution of 2 (1.03 g, 3.01 mmol) in 4 N HCl
in dioxane (3 mL) was stirred at room temperature for 1.5 h
before addition of water (5 mL). Solid NaHCO3 was added until
basic. The mixture was diluted with Et2O (25 mL) and water
(25 mL) and the phases were separated. The aqueous phase
was extracted with more Et2O (15 mL) and the combined
organic extracts were dried over MgSO4, filtered, and concen-
trated. The concentrate was purified by flash chromatography
(15% EtOAc/hexanes) to give 245 mg of 8e (34% yield): 1H
NMR (300 MHz, acetone-d6) δ 7.30 (t, J ) 9.2 Hz, 1H), 6.94
(dd, J ) 9.2, 4.0 Hz, 1H), 5.58 (br s, 2H); 19F NMR (282 MHz,
acetone-d6) δ -75.4 (s, 3F), -132.1 (s, 1F).
2,2-Dim e t h yl-N -(4-ch lor o-3-flu or op h e n yl)p r op a n a -
m id e (4). A solution of 3 (2.00 g, 10.2 mmol) in DMF (20 mL)
containing N-chlorosuccinimide (1.50 g, 11.2 mmol) was heated
at 80 °C for approximately 20 min before cooling to room

Inhibition of Mutant Variants of HIV-1
J ournal of Medicinal Chemistry, 2000, Vol. 43, No. 10 2025
temperature. The mixture was diluted with EtOAc; washed
with saturated aqueous NaHCO3, water, and saturated aque-
ous NaCl; dried over MgSO4; filtered; and concentrated to
afford a white solid, which was purified by flash chromatog-
raphy (10% EtOAc/hexanes) to give 1.48 g of 4 as a white solid
(63% yield): 1H NMR (300 MHz, acetone-d6) δ 8.85 (br s, 1H),
7.86 (dd, J ) 12, 2.0 Hz, 1H), 7.44-7.34 (m, 2H), 1.25 (s, 9H);
19F NMR (282 MHz, acetone-d6) δ -116.74 to -116.89 (m, 1F).
Anal. (C11H13ClFNO) C, H, N.
d6) δ 7.72 (d, J ) 8.4 Hz. 1H), 7.51 (d, J ) 8.4 Hz, 1H), 1.68 (s,
9H); 19F NMR (282 MHz, acetone-d6) δ -77.4 (s, 3F).
1-(2-Am in o-5,6-d ich lor op h e n yl)-2,2,2-t r iflu or oe t h a -
n on e (8i). A solution of 7 (0.76 g, 2.12 mmol) in 4 N HCl in
dioxane (2 mL) was stirred at room temperature for 1.5 h
before addition of water. Solid NaHCO3 (CO2 evolution!) was
added until the mixture was basic. The mixture was diluted
with Et2O (25 mL) and water (25 mL), and the phases were
separated. The aqueous phase was extracted with more Et2O
(15 mL), and the combined organic extracts were dried over
MgSO4, filtered, and concentrated. The concentrate was puri-
fied by flash chromatography (15% EtOAc/hexanes) to give 100
mg of 8i (19% yield); the major byproduct was recovered 6:
1H NMR (300 MHz, acetone-d6) δ 7.41 (d, J ) 9.2 Hz, 1H),
6.92 (d, J ) 9.2 Hz, 1H), 5.69 (br s, 2H); 19F NMR (282 MHz,
acetone-d6) δ -75.6 (s, 3F).
Gen er a l P r oced u r e for Am in ol F or m a tion . Procedure
A. To a solution of ketone 8 in anhydrous THF (0.5 M) were
added N,N-(dimethylamino)pyridine (0.1 equiv) and trimeth-
ylsilylisocyanate (2.6 equiv). The mixture was stirred at room
temperature for 5 h before addition of tetrabutylammoniun
fluoride (2 equiv of a 1 M solution in THF). The mixture was
stirred at room temperature for an additional 0.5 h; diluted
with EtOAc; washed sequentially with 1 N HCl, saturated
aqueous NaHCO3, and saturated aqueous NaCl; dried over
MgSO4, filtered; and concentrated. The resulting solid was
triturated with hexanes and dried.
2,2-Dim eth yl-N-(4-ch lor o-3-flu or o-2-tr iflu or oacetylph e-
n yl)p r op a n a m id e (5). To a solution of 4 (1.00 g, 4.35 mmol)
in anhydrous THF (14.5 mL) at -78 °C was added n-BuLi (6.5
mL of 1.6 M solution in hexanes, 10.4 mmol) via an addition
funnel over 10 min. The mixture was aged at -78 °C for 1.5 h
before the dropwise addition of ethyl trifluoroaceate (1.4 g, 1.2
mL, 10 mmol). The mixture was stirred at -78 °C for 0.5 h
and then the reaction was allowed to warm to room temper-
ature. The reaction was quenched by addition of saturated
aqueous NH4Cl and poured into Et2O (50 mL) and water (50
mL). The organic phase was isolated, washed with saturated
aqueous NaCl, dried over MgSO4, filtered and concentrated.
The concentrate was purified by flash chromatography to yield
1
1.20 g of 5 (85% yield): mp 106-108 °C; H NMR (300 MHz,
acetone-d6) δ 9.61 (br s, 1H), 7.70 (t, J ) 8.4 Hz, 1H), 7.28 (dd,
J ) 8.8, 1.5 Hz, 1), 1.21 (s, 9H); 19F NMR (282 MHz, acetone-
d6) δ -76.1 to -76.2 (m, 3F), -109.8 to -110.2 (m, 1F). Anal.
(C13H12ClF4NO2) C, H, N.
1-(2-Am in o-5-ch lor o-6-flu or op h en yl)-2,2,2-tr iflu or oet-
h a n on e (8h ). A solution of 5 (5.32 g, 16.3 mmol) in ethylene
glycol dimethyl ether (13 mL) and 6 N HCl (65 mL) was heated
at reflux for 1.5 h. The mixture was cooled to room tempera-
ture, and solid Na2CO3 (CO2 evolution!) was slowly added until
the solution was basic. Water (150 mL) was added and the
mixture was extract with Et2O (200 mL). The aqueous phase
was back-extract with Et2O (100 mL), and the combined
organic extracts were dried over MgSO4, filtered, and concen-
trated. Baseline material was removed by passage through a
plug of silica (10% EtOAc/hexanes) to give 3.45 g of 8h as a
yellow oil which was used without further purification (88%
yield): 1H NMR (300 MHz, acetone-d6) δ 7.48-7.39 (m, 3H),
6.84 (dd, J ) 9.2, 1.5 Hz, 1H); 19F NMR (282 MHz, acetone-
d6) δ -76.1 to -76.2 (m, 1F), -76.0 to -76.2 (m, 3F).
(3,4-Dich lor op h en yl)ca r ba m ic Acid ter t-Bu tyl Ester
(6). To a solution of 3,4-dichloroaniline (10.0 g, 61.7 mmol) in
anhydrous THF (62 mL) was slowly added sodium bis-
(trimethylsilyl)amide (123 mL of 1.0 M solution in THF). The
reaction was stirred at room temperature for 1.5 h before
addition of a solution of Boc2O (13.5 g, 61.7 mmol) in anhydrous
THF (5 mL). The mixture was aged at room temperature for
3 h, concentrated under reduced pressure, diluted with EtOAc
(200 mL), and washed with 0.5 N HCl (250 mL). The aqueous
phase was back-extracted with EtOAc (100 mL), and the
combined organic extracts were dried over MgSO4, filtered, and
concentrated to give 15.4 g of crude 6, which was used without
further purification (95% yield): mp 112-113 °C (lit.26 mp
114-115 °C); 1H NMR (300 MHz, acetone-d6) δ 8.70 (br s, 1H),
7.88 (s, 1H), 7.43 (s, 2), 1.46 (s, 9H).
[3,4-Dich lor o-2-(2,2,2-tr iflu r oeth an on e)ph en yl]car bam -
ic Acid ter t-Bu tyl Ester (7). To a solution of anhydrous THF
(14 mL) containing TMEDA (2.22 g, 2.88 mL, 19.1 mmol) at
-78 °C was added t-BuLi (11.2 mL of 1.7 M solution). The
mixture was aged at -78 °C for 0.5 h, before addition of a -78
°C solution of 6 (2.50 g, 9.54 mmol) in anhydrous THF (19 mL)
via cannula over approximately 10 min. The mixture was aged
at -78 °C for 2 h, and then ethyl trifluoroacetate (2.71 g, 2.27
mL, 19.1 mmol) was added. The cooling bath was removed and
the mixture was allowed to warm to room temperature. The
reaction was quenched with saturated aqueous NH4Cl after 2
h and extracted with EtOAc (150 mL), washed with saturated
aqueous NaHCO3 (80 mL) and aqueous NaCl (80 mL), dried
over MgSO4, filtered, and concentrated. The concentrate was
purified by flash chromatography (15% EtOAc/hexanes) to give
0.76 g of 7 as an impure yellow oil which was used without
further purification (22% yield): 1H NMR (300 MHz, acetone-
P r oced u r e B. To a solution of ketone 8 in acetic acid (0.55
M) and water (5.5 M) was added potassium cyanate (2.5 equiv).
The resulting mixture was stirred at room temperature
overnight, diluted with water (4 mL/mmol of 8), and stirred
for 15 min before collection of the precipitate. The white solid
was washed with water and dried under reduced pressure.
3,4-D ih y d r o -5-flu o r o -4-h y d r o x y -4-t r iflu o r o m e t h -
ylqu in a zolin -2(1H)-on e (9a ) was prepared as described in
procedure A to afford 323 mg of 9a (85% yield): 1H NMR (300
MHz, acetone-d6) δ 9.08 (br s, 1H), 7.43-7.30 (m, 2H), 6.96
(br s, 1H), 6.85-6.74 (m, 2H); 19F NMR (282 MHz, acetone-
d6) δ -86.4 (s, 3F), -111.8 (s, 1F).
5-C h lo r o -3,4-d ih y d r o -4-h y d r o x y -4-t r iflu o r o m e t h -
ylqu in a zolin -2(1H)-on e (9b) was prepared as described in
procedure A to afford 234 mg of 9b (99% yield): 1H NMR (300
MHz, acetone-d6) δ 9.03 (br s, 1H), 7.33 (t, J ) 8.1 Hz, 1H),
7.26 (br s, 1H), 7.07 (d, J ) 8.1 Hz, 1H), 7.00 (d, J ) 8.4 Hz,
1H), 6.94 (br s, 1H); 19F NMR (282 MHz, acetone-d6) δ -85.6
(s, 3F).
5,6-Diflu or o-3,4-d ih yd r o-4-h yd r oxy-4-t r iflu or om et h -
ylqu in a zolin -2(1H)-on e (9c) was prepared as described in
procedure A to afford 110.9 g of 9c (92% yield): mp 215 (dec);
1H NMR (300 MHz, acetone-d6) δ 9.13 (br s, 1H), 7.45-7.32
(m, 2H), 7.18 (br s, 1H), 6.85-6.80 (m, 1H); 19F NMR (282
MHz, acetone-d6) δ -86.6 (d, J ) 17.2 Hz, 3F), -137.5 to
-137.7 (m, 1F), -148.5 to -148.6 (m, 1F). Anal. (C9H5F5N2O2
‚0.2C4H8O2) C, H, N.
6-C h lo r o -3,4-d ih y d r o -4-h y d r o x y -4-t r iflu o r o m e t h -
ylqu in a zolin -2(1H)-on e (9d ) was prepared as described in
procedure B to afford 2.70 g of 9d (85% yield): mp 235 °C; 1H
NMR (300 MHz, acetone-d6) δ 9.06 (br s, 1H), 7.48 (s, 1H),
7.40 (br s, 1H), 7.34 (dd, J ) 8.8, 2.6 Hz, 1H), 6.97 (d, J ) 8.8
Hz, 1H); 19F NMR (282 MHz, acetone-d6) δ -86.4 (s, 3F); MS
(CI) 266 (MH+, 100). Anal. (C9H6ClF3N2O2) C, H, N.
5-Ch lor o-3,4-d ih yd r o-6-flu or o-4-h yd r oxy-4-tr iflu or om -
eth ylqu in a zolin -2(1H)-on e (9e) was prepared as described
in procedure A to afford 2.10 g of 9e (99% yield): mp 220 °C
(dec); 1H NMR (300 MHz, acetone-d6) δ 9.08 (br s, 1H), 7.39-
7.33 (m, 2H), 7.21 (br s, 1H), 7.08-7.03 (m, 1H); 19F NMR (282
MHz, acetone-d6) δ -85.5 (s, 3F), -121.9 (s, 1F). Anal. (C9H5-
ClF4N2O2‚0.1C3H6O) C, H, N.
3,4-D ih y d r o -6-flu o r o -4-h y d r o x y -4-t r iflu o r o m e t h -
ylqu in a zolin -2(1H)-on e (9f) was prepared as described in
procedure A to afford 3.22 g of 9f (87% yield): mp 202-204
°C (dec); 1H NMR (300 MHz, acetone-d6) δ 9.02 (br s, 1H), 7.38
(br s, 1H), 7.30 (dd, J ) 9.2, 1.8 Hz, 1H), 7.23-7.16 (m, 1H),

2026 J ournal of Medicinal Chemistry, 2000, Vol. 43, No. 10
Corbett et al.
7.07-7.00 (m, 2H); 19F NMR (282 MHz, acetone-d6) δ -86.2
(s, 3F), -123.4 (s, 1F); MS (CI) 234 (M-H2O, 100).
6-Ch lor o-5-flu or o-4-tr iflu or om eth ylqu in a zolin -2(1H)-
on e (10h ). Prepared according to the general procedure using
xylenes to afford 1.39 g of 10h (79% yield): mp 239 °C (dec);
1H NMR (300 MHz, acetone-d6) δ 7.94-7.88 (m, 1H), 7.43-
7.40 (m, 2H); 19F NMR (282 MHz, acetone-d6) δ -70.5 to -70.7
(m, 3F), -110.2 to -110.5 (m, 1F).
3,4-Dih yd r o-4-h yd r oxy-6-m e t h oxy-4-t r iflu or om e t h -
ylqu in a zolin -2(1H)-on e (9g) was prepared as described in
procedure B to afford 244 mg of 9g (83% yield): mp 195 °C
1
(dec); H NMR (300 MHz, acetone-d6) δ 8.81 (br s, 1H), 7.17
5,6-Dich lor o-4-t r iflu or om et h ylq u in a zolin -2(1H )-on e
(10i). Prepared according to the general procedure using
xylenes to afford 75 mg of 10i (69% yield): 1H NMR (300 MHz,
(br s, 1H), 7.11 (br s, 1H), 7.00-6.92 (m, 2H), 6.83 (s, 1H),
3.76 (s, 3H); 19F NMR (282 MHz, acetone-d6) δ -86.0 (s, 3F);
HRMS calcd for C10H9F3N2O2 [M + H]+ 246.0613, 246.0616
found. Anal. (C10H9F3N2O3) C, H, N.
6-Ch lor o-3,4-d ih yd r o-5-flu or o-4-h yd r oxy-4-tr iflu or om -
eth ylqu in a zolin -2(1H)-on e (9h ) was prepared as described
in procedure B to afford 1.93 g of 9h (79% yield): mp 216 °C
(dec); 1H NMR (300 MHz, acetone-d6) δ 9.27 (br s, 1H), 7.55-
7.49 (m, 2H), 6.88 (dd, J ) 8.8, 1.54 Hz, 1H); 19F NMR (282
MHz, acetone-d6) δ -86.5 to -86.6 (m, 3F), -112.8 to -113.0
(m, 1F).
acetone-d6) δ 7.90 (d, J ) 8.1 Hz, 1H), 7.58-7.55 (m, 2H); 19
NMR (282 MHz, acetone-d6) δ -63.8 (s, 3F).
F
Gen er a l P r oced u r e for Lith iu m Acetylid e Ad d ition to
Ketim in es 10. A 0 °C solution of lithiated acetylide (4 equiv)
in anhydrous THF (0.5 M) was cannulated into a solution of
ketimine 10 in anhydrous THF (0.2 M) at - 78 °C. To this
was then added BF3‚OEt2 (0.5 equiv), the -78 °C cooling bath
was removed, and the mixture was allowed to warm to room
temperature. After stirring overnight at room temperature,
the reaction was quenched by the addition of 1 M citric acid
and diluted with EtOAc, and the phases were separated. The
organic solution was sequentially washed with water, satu-
rated aqueous NaHCO3, and saturated aqueous NaCl; dried
over MgSO4; filtered; and concentrated. The crude product was
purified either by flash chromatography, HPLC, or crystal-
lization.
5,6-Dich lor o-3,4-d ih yd r o-4-h yd r oxy-4-t r iflu or om et h -
ylqu in a zolin -2(1H)-on e (9i) was prepared as described in
procedure A to afford 116 mg of 9i (99% yield): mp 249-252
1
°C; H NMR (300 MHz, acetone-d6) δ 9.11 (br s, 1H), 7.57 (d,
J ) 8.8 Hz, 1H), 7.37 (br s, 1H), 7.04-7.01 (m, 2H); 19F NMR
(282 MHz, acetone-d6) δ -85.4 (s, 3F).
Gen er a l P r oced u r e for Ketim in e F or m a tion . A solution
of aminol 9 in either toluene or xylene containing 4 Å
molecular sieves was heated at reflux until the CF3 signal of
9 was no longer present as determined by 19F NMR. The
solution was cooled to room temperature, and the molecular
sieves were removed by vacuum filtration and rinsed with
acetone. The filtrate was concentrated and triturated with
hexanes to afford the desired ketimine 10.
5-F lu or o-4-tr iflu or om eth ylqu in a zolin -2(1H)-on e (10a ).
Prepared according to the general procedure using xylenes to
afford 238 mg of 10a (80% yield): mp >275 °C; 1H NMR (300
MHz, acetone-d6) δ 7.90-7.83 (m, 1H), 7.36 (d, J ) 8.4 Hz,
1H), 7.15-7.08 (m, 1H); 19F NMR (282 MHz, acetone-d6) δ
-70.7 (s, 3F), -108.7 (s, 1F); Anal. (C9H4F4N2O) C, H, N.
4-(Cyclop r op yleth yn yl)-3,4-d ih yd r o-5-flu or o-4-(tr iflu o-
r om eth yl)-2(1H)-qu in a zolin on e (11). Prepared according to
the general procedure and purified by HPLC (2.5% MeOH/
CH2Cl2) to afford 64 mg of 11 (59% yield): mp 168 °C (dec);
1H NMR (300 MHz, acetone-d6) δ 9.20 (br s, 1H), 7.57 (br s,
1H), 7.42-7.35 (m, 1H), 6.84-6.77 (m, 2H), 1.41-1.32 (m, 1H),
0.88-0.81 (m, 2H), 0.72-0.67 (m, 2H); 19F NMR (282 MHz,
acetone-d6) δ -83.2 (s, 3F), -110.5 (s, 1F); HRMS calcd for
C
14H11F4N2O [M + H]+ 299.0808, found 299.0799. Anal.
(C14H10F4N2O‚0.25H2O) C, H, N.
5-Ch lor o-4-(cyclop r op yleth yn yl)-3,4-d ih yd r o-4-(tr iflu -
or om eth yl)-2(1H)-qu in a zolin on e (12). Prepared according
to the general procedure and purified by HPLC (2.5% MeOH/
CH2Cl2) and crystallized from acetone to afford 25 mg of 12
(20% yield): mp 184 °C; 1H NMR (300 MHz, acetone-d6) δ 8.98
(br s, 1H), 7.36-7.31 (m, 1H), 7.10 (dd, J ) 8.1, 1.1 Hz, 1H),
6.99 (d, J ) 8.4 Hz, 1H), 1.42-1.37 (m, 1H), 0.87-0.72 (m,
4H); 19F NMR (282 MHz, acetone-d6) δ -81.6 (s, 3F); HRMS
calcd for C14H11ClF3N2O [M + H]+ 315.0512, found 315.0494.
Anal. (C14H10ClF3N2O‚0.3H2O) C, H, N.
5-Ch lor o-4-tr iflu or om eth ylqu in a zolin -2(1H)-on e (10b).
Prepared according to the general procedure using xylenes to
1
afford 177 mg of 10b (81% yield): mp 222 °C (dec); H NMR
(300 MHz, acetone-d6) δ 7.75 (t, J ) 8.1 Hz, 1H), 7.52 (d, J )
8.1 Hz, 1H), 7.43 (d, J ) 7.7 Hz, 1H); 19F NMR (282 MHz,
acetone-d6) δ -64.3 (s, 3F); Anal. (C9H4ClF3N2O‚0.2C3H6O) C,
H, N.
5,6-Diflu or o-4-t r iflu or om et h ylq u in a zolin -2(1H )-on e
(10c). Prepared according to the general procedure using
xylenes to afford 9.91 g of 10c (97% yield): mp 208 °C (dec);
1H NMR (300 MHz, acetone-d6) δ 7.92-7.83 (m, 1H), 7.46-
7.44 (m, 1H); 19F NMR (282 MHz, acetone-d6) δ -70.7 (d, J )
38.7 Hz, 3F), -136.7 (s, 1F), -146.5 to -146.6 (m, 1F); Anal.
(C10H7F5N2O2) C, H, N.
4-(Cyclop r op yleth yn yl)-5,6-d iflu or o-3,4-d ih yd r o-4-(tr i-
flu or om eth yl)-2(1H)-qu in a zolin on e (13). Prepared accord-
ing to the general procedure and purified by crystallization
from acetone to afford 8.16 g of 13 (63% yield): mp 192 °C; 1H
NMR (300 MHz, acetone-d6) δ 9.01 (br s, 1H), 7.46 (br s, 1H),
7.44-7.35 (m, 1H), 6.86-6.81 (m, 1H), 1.41-1.37 (m, 1H),
0.90-0.83 (m, 1H), 0.74-0.69 (m, 1H); 19F NMR (282 MHz,
acetone-d6) δ -83.3 (d, J ) 12.9 Hz, 3F), -136.0 to -136.2
(m, 1F), -148.1 to -148.3 (m, 1F); HRMS (CI) calcd for
6-Ch lor o-4-tr iflu or om eth ylqu in a zolin -2(1H)-on e (10d ).
Prepared according to the general procedure using toluene to
1
14H10F5N2O [M + H]+ 317.0713, found 317.0708. Anal.
afford 2.30 g of 10d (96% yield): mp 217 °C (dec); H NMR
C
(300 MHz, acetone-d6) δ 7.86-7.82 (m, 2H), 7.61 (d, J ) 8.8
(C14H9H5N2O) C, H, N.
Hz, 1H); 19F NMR (282 MHz, acetone-d6) δ -67.9 (s, 3F).
6-Ch lor o-4-(cyclop r op yleth yn yl)-3,4-d ih yd r o-4-(tr iflu -
or om eth yl)-2(1H)-qu in a zolin on e (14). Prepared according
to the general procedure and purified by flash chromatography
(3% MeOH/CH2Cl2) to afford 3.85 g of 14 (97% yield): mp
86.6-88 °C; 1H NMR (300 MHz, acetone-d6) δ 8.95 (br s, 1H),
7.51 (br s, 1H), 7.43 (br s, 1H), 7.40 (dd, J ) 8.8, 2.4 Hz, 1H),
7.02 (d, J ) 8.8 Hz, 1H), 1.49-1.41 (m, 1H), 0.93-0.82 (m,
1H), 0.77-0.74 (m, 1H); 19F NMR (282 MHz, acetone-d6) δ
-83.0 (s, 3F); HRMS calcd for C14H10ClF3N2O [M + H]+
315.0512, found 315.0516. Anal. (C14H10N2ClF3O‚0.25H2O) C,
H, N.
5-Ch lor o-6-flu or o-4-tr iflu or om eth ylqu in a zolin -2(1H)-
on e (10e). Prepared according to the general procedure using
xylenes to afford 175 mg of 10e (65% yield): mp 190 °C (dec);
1H NMR (300 MHz, acetone-d6) δ 7.79 (br s, 1H), 7.64 (br s,
1H); 19F NMR (282 MHz, acetone-d6) δ -64.2 (s, 3F), -116.7
(s, 1F).
6-F lu or o-4-tr iflu or om eth ylqu in a zolin -2(1H)-on e (10f).
Prepared according to the general procedure using toluene to
afford 6.64 g of 10f (93% yield): mp 156 °C (dec); 1H NMR
(300 MHz, acetone-d6) δ 7.77-7.71 (m, 1H), 7.64-7.59 (m, 3H);
19F NMR (282 MHz, acetone-d6) δ -68.2 (s, 3F), -119.5 (s,
1F).
6-Meth oxy-4-tr iflu or om eth ylqu in a zolin -2(1H)-on e (10
g). Prepared according to the general procedure using toluene
to afford 0.50 g of 10g (93% yield): mp 267 °C (dec); 1H NMR
(300 MHz, acetone-d6) δ 7.52 (br s, 2H), 7.27 (s, 1H), 3.90 (s,
3H); 19F NMR (282 MHz, acetone-d6) δ -68.1 (s, 3F).
5-Ch lor o-4-(cyclop r op yleth yn yl)-3,4-d ih yd r o-6-flu or o-
4-(tr iflu or om eth yl)-2(1H)-qu in a zolin on e (15). Prepared
according to the general procedure and purified by HPLC (2.5%
MeOH/CH2Cl2) to afford 70 mg of 15 (56% yield): mp 88-90
1
°C; H NMR (300 MHz, acetone-d6) δ 9.23 (br s, 1H), 7.64 (br
s, 1H), 7.37 (t, J ) 8.8 Hz, 1H), 7.03 (dd, J ) 8.8, 4.4 Hz, 1H),
1.46-1.37 (m, 1H), 0.89-0.73 (m, 4H); 19F NMR (282 MHz,

Inhibition of Mutant Variants of HIV-1
J ournal of Medicinal Chemistry, 2000, Vol. 43, No. 10 2027
acetone-d6) δ -81.6 (m, 3F), -121.0 to -121.0 (m, 1F); HRMS
calcd for C14H10ClF4N2O [M + H]+ 333.0418, found 333.0417.
Anal. (C14H9ClF4N2O‚0.75C3H6O) C, H, N.
3,4-Dih yd r o-6-flu or o-4-(3-m eth ylbu tyn -1-yl)-4-(tr iflu o-
r om eth yl)-2(1H)-qu in a zolin on e (23). Prepared according to
the general procedure and purified by HPLC (2.5% MeOH/
CH2Cl2) to afford 24 mg of 23 (19% yield): mp 158 °C; 1H NMR
(300 MHz, acetone-d6) δ 9.07 (br s, 1H), 7.60 (br s, 1H), 7.32-
7.30 (m, 1H), 7.24-7.16 (m, 1H), 7.05-6.99 (m, 1H), 2.77-
2.67 (m, 1H), 1.20 (dd, J ) 7.0, 2.6 Hz, 6H); 19F NMR (282
MHz, acetone-d6) δ -83.0 (s, 3F), -123.4 to -123.5 (s, 1F);
HRMS calcd for C14H13F4N2O [M + H]+ 301.0964, found
301.0962. Anal. (C14H12F4N2O) C, H, N.
4-(Cyclop r op yleth yn yl)-3,4-d ih yd r o-6-flu or o-4-(tr iflu o-
r om eth yl)-2(1H)-qu in a zolin on e (16). Prepared according to
the general procedure and purified by HPLC (2.5% MeOH/
CH2Cl2) to afford 44 mg of 16 (34% yield): mp 155 °C; 1H NMR
(300 MHz, acetone-d6) δ 8.86 (br s, 1H), 7.36 (br s, 1H), 7.30-
7.27 (m, 1H), 7.22-7.15 (m, 1H), 7.04-6.99 (m, 1H), 1.47-
1.42 (m, 1H), 0.90-0.87 (m, 2H), 0.76-0.75 (m, 2H); 19F NMR
(282 MHz, acetone-d6) δ -82.9 (m, 3F), -123.4 to -123.4 (m,
1F); HRMS calcd for C14H11F4N2O [M + H]+ 299.0808, found
299.0800. Anal. (C14H10F4N2O) C, H, N.
3,4-Dih yd r o-6-m eth oxy-4-(3-m eth ylbu tyn -1-yl)-4-(tr if-
lu or om eth yl)-2(1H)-qu in a zolin on e (24). Prepared accord-
ing to the general procedure and purified by flash chromatog-
raphy (3% MeOH/CH2Cl2) to afford 30 mg of 24 (24% yield):
4-(Cyclop r op yleth yn yl)-3,4-d ih yd r o-6-m eth oxy-4-(tr i-
flu or om eth yl)-2(1H)-qu in a zolin on e (17). Prepared accord-
ing to the general procedure and purified by HPLC (2.5%
MeOH/CH2Cl2) to afford 103 mg of 17 (81% yield): mp 208
1
mp 228-229 °C; H NMR (300 MHz, acetone-d6) δ 8.72 (br s,
1H), 7.27 (br s, 1H), 7.10 (br s, 1H), 7.00-6.91 (m, 2H), 3.77
(s, 3H), 2.73-2.67 (m, 1H), 1.20 (dd, J ) 7.0, 1.5 Hz, 6H); 19
F
NMR (282 MHz, acetone-d6) δ -82.7 (s, 3F); HRMS calcd for
1
°C; H NMR (300 MHz, acetone-d6) δ 8.77 (br s, 1H), 7.29 (br
C
15H16F3N2O2 [M + H]+ 313.1164, found 313.1159. Anal.
s, 1H), 7.06 (br s, 1H), 6.99-6.90 (m, 2H), 3.77 (s, 3H), 1.46-
1.38 (m, 1H), 0.91-0.85 (m, 2H), 0.79-0.72 (m, 2H); 19F NMR
(282 MHz, acetone-d6) δ -82.6 (s, 3F); HRMS calcd for
C15H14F3N2O2 [M + H]+ 311.1007, found 311.1000. Anal.
(C15H12F3N2O2‚O.5 C3H6O) C, H, N.
(C15H15F3N2O2) C, H, N.
4-(1-Bu tyn -1-yl)-5,6-d iflu or o-3,4-d ih yd r o-4-(tr iflu or om -
eth yl)-2(1H)-qu in a zolin on e (25). Prepared according to the
general procedure and purified by HPLC (2.5% MeOH/CH2-
Cl2) to afford 69 mg of 25 (57% yield): mp 191-194 °C; 1H
NMR (300 MHz, acetone-d6) δ 9.03 (br s, 1H), 7.50 (br s, 1H),
7.45-7.35 (m, 1H), 6.87-6.82 (m, 1H), 2.34-2.27 (m, 2H),
1.20-1.15 (m, 3H); 19F NMR (282 MHz, acetone-d6) δ -83.3
(d, J ) 12.9 Hz, 3F), -135.8 to -136.0 (m, 1F), -148.2 to
-148.3 (m, 1F); HRMS calcd for C13H10F5N2O [M + H]+
305.0713, found 305.0711. Anal. (C13H9F5N2O) C, H, N.
4-(1-Bu t yn -1-yl)-6-ch lor o-3,4-d ih yd r o-4-(t r iflu or om e-
th yl)-2(1H)-qu in a zolin on e (26). Prepared according to the
general procedure and purified by HPLC (2.5% MeOH/CH2-
Cl2) to afford 25 mg of 26 (20% yield): mp 217-219 °C; 1H
NMR (300 MHz, acetone-d6) δ 9.05 (br s, 1H), 7.54 (br s, 2H),
7.41-7.39 (m, 1H), 7.02 (d, J ) 8.4 Hz, 1H), 2.36-2.32 (m,
2H), 2.18-1.13 (m, 3H); 19F NMR (282 MHz, acetone-d6) δ
-83.0 (s, 3F); HRMS calcd for C13H10ClF3N2O [M + H]+
303.0512, found 303.0519. Anal. (C13H10ClF3N2O) C, H, N.
4-(1-Bu t yn -1-yl)-3,4-d ih yd r o-6-flu or o-4-(t r iflu or om e-
th yl)-2(1H)-qu in a zolin on e (27). Prepared according to the
general procedure and purified by HPLC (2.5% MeOH/CH2-
6-Ch lor o-4-(cyclop r op yleth yn yl)-3,4-d ih yd r o-5-flu or o-
4-(tr iflu or om eth yl)-2(1H)-qu in a zolin on e (18). Prepared
according to the general procedure and purified by HPLC (2.5%
MeOH/CH2Cl2) to afford 156 mg of 18 (62% yield): mp 202-
203 °C; 1H NMR (300 MHz, acetone-d6) δ 9.11 (br s, 1H), 7.56-
7.50 (m, 2H), 6.88 (dd, J ) 8.8, 1.4 Hz, 1H), 1.44-1.36 (m,
1H), 0.90-0.84 (m, 2H), 0.79-0.70 (m, 2H); 19F NMR (282
MHz, acetone-d6) δ -83.2 (s, 3F), -111.7 (s, 1F); HRMS Calc′d
for C14H10ClF4N2O [M + H]+ 333.0418, found 333.0431. Anal.
(C14H9ClF4N2O‚0.3C3H6O) C, H, N.
4-(Cyclop r op yleth yn yl)-5,6-d ich lor o-3,4-d ih yd r o-4-(tr i-
flu or om eth yl)-2(1H)-qu in a zolin on e (19). Prepared accord-
ing to the general procedure and purified by HPLC (2.5%
MeOH/CH2Cl2) to afford 20 mg of 19 (16% yield): mp 175-
176 °C; 1H NMR (300 MHz, acetone-d6) δ 9.05 (br s, 1H), 7.60
(d, J ) 8.8 Hz, 1H), 7.41 (br s, 1H), 7.04 (d, J ) 8.8 Hz, 1H),
1.48-1.42 (m, 1H), 0.86-0.84 (m, 2H), 0.77-0.76 (m, 2H); 19
F
NMR (282 MHz, acetone-d6) δ -81.3 (s, 3F); HRMS calcd for
C
14H10Cl2F3N2O [M + H]+ 349.0122, found 349.0141; HPLC
1
Cl2) to afford 40 mg of 27 (33% yield): mp 190 °C; H NMR
purity, 96.4%.
(300 MHz, acetone-d6) δ 8.86 (br s, 1H), 7.38 (br s, 1H), 7.34-
7.31 (m, 1H), 7.22-7.16 (m, 1H), 7.05-7.00 (m, 1H), 2.04-
2.01 (m, 2H), 1.19-1.14 (m, 3H); 19F NMR (282 MHz, acetone-
d6) δ -75.4 (s, 3F), -123.4 to -123.5 (m, 1F); HRMS calcd for
5,6-Diflu or o-3,4-d ih yd r o-4-(3-m eth ylbu tyn -1-yl)-4-(tr i-
flu or om eth yl)-2(1H)-qu in a zolin on e (20). Prepared accord-
ing to the general procedure and purified by crystallization
from acetone to afford 6.77 g of 20 (74% yield): mp 86.5-88.5
C
13H11F4N2O [M + H]+ 287.0808, found 287.0807. Anal.
1
°C; H NMR (300 MHz, acetone-d6) δ 9.02 (br s, 1H), 7.50 (br
(C13H10F4N2O) C, H, N.
s, 1H), 7.44-7.35 (m, 1H), 6.87-6.82 (m, 1H), 2.69-2.65 (m,
1H), 1.17 (d, J ) 7.0 Hz, 6H); 19F NMR (282 MHz, acetone-d6)
δ -83.4 (d, J ) 12.9 Hz, 1F), -135.8 to -135.9 (m, 1F), -148.1
to -148.3 (m, 1F); HRMS calcd for C14H12F5N2O [M + H]+
319.0870, found 319.0874. Anal. (C14H11F5N2O) C, H, N.
5,6-Diflu or o-3,4-d ih yd r o-4-[(2-p yr id yl)eth yn yl]-4-(tr i-
flu or om eth yl)-2(1H)-qu in a zolin on e (28). Prepared accord-
ing to the general procedure and purified by HPLC (2.5%
MeOH/CH2Cl2) to afford 83 mg of 28 (59% yield): mp 219-
220 °C; 1H NMR (300 MHz, acetone-d6) δ 9.15 (br s, 1H), 8.61
(d, J ) 4.4 Hz, 1H), 7.88-7.82 (m, 2H), 7.63 (dd, J ) 7.0, 1.1
Hz, 1H), 7.47-7.42 (m, 2H), 6.94-6.88 (m, 1H); 19F NMR (282
MHz, acetone-d6) δ -82.8 (d, J ) 12.9 Hz, 3F), -135.8 to
-135.9 (m, 1F), -147.9 to -148.0 (m, 1F); HRMS calcd for
6-Ch lor o-3,4-d ih yd r o-4-(3-m eth ylbu tyn -1-yl)-4-(tr iflu o-
r om eth yl)-2(1H)-qu in a zolin on e (21). Prepared according to
the general procedure and purified by flash chromatography
(35% EtOAc/hexanes) to afford 26 mg of 21 (41% yield): mp
180 °C; 1H NMR (300 MHz,) δ 9.08 (br s, 1H), 7.59 (br s, 1H),
7.53 (br s, 1H), 7.40 (dd, J ) 8.4, 2.2 Hz, 1H), 7.02 (d, J ) 8.8
Hz, 1H), 2.81-2.68 (m, 1H), 1.20 (dd, J ) 6.6 Hz, 6H); 19F NMR
C
16H9F5N3O [M + H]+ 354.0666, found 354.0678. Anal.
(C16H8F5N3O‚0.45C4H8O2) C, H, N.
6-Ch lor o-3,4-d ih yd r o-4-[(2-p yr id yl)eth yn yl]-4-(tr iflu o-
r om eth yl)-2(1H)-qu in a zolin on e (29). Prepared according to
the general procedure and purified by HPLC (2.5% MeOH/
CH2Cl2) to afford 110 mg of 29 (78% yield): mp 105 °C (dec);
1H NMR (300 MHz, acetone-d 6) δ 9.14 (br s, 1H), 8.64-8.61
(m, 1H), 7.89-7.84 (m, 2H), 7.70-7.66 (m, 2H), 7.48-7.43 (m,
2H), 7.09 (d, J ) 8.8 Hz, 1H); 19F NMR (282 MHz, acetone-d6)
δ -82.5 (s, 3F); HRMS calcd for C16H10ClF3N3O [M + H]+
352.0465, found 352.0470. Anal. (C16H9ClF3N3O‚0.12H2O) C,
H, N.
(282 MHz, acetone-d6) δ -83.1 (s, 3F); HRMS calcd for C14H12
ClF3N2O [M + H]+ 317.0669, found 317.0694. Anal. (C14H12
ClF3N2O) C, H, N.
-
-
5-Ch lor o-3,4-d ih yd r o-6-flu or o-4-(3-m eth ylbu tyn -1-yl)-
4-(tr iflu or om eth yl)-2(1H)-qu in a zolin on e (22). Prepared
according to the general procedure and purified by HPLC (2.5%
MeOH/CH2Cl2) to afford 28 mg of 22 (22% yield): mp 208 °C;
1H NMR (300 MHz, acetone-d6) δ 9.19 (br s, 1H), 7.62 (br s,
1H), 7.04 (dd, J ) 9.2, 4.8 Hz, 1H), 2.74-2.65 (m, 1H), 1.18
(d, J ) 7.0 Hz, 1H); 19F NMR (282 MHz, acetone-d6) δ -81.6
(s, 3F), -121.0 (s, 1F); HRMS calcd for C14H12ClF4N2O [M +
H]+ 335.0574, found 355.0570. Anal. (C14H11ClF4N2O) C, H,
N.
5-Ch lor o-3,4-d ih yd r o-6-flu or o-4-[(2-p yr id yl)eth yn yl]-4-
(tr iflu or om eth yl)-2(1H)-qu in a zolin on e (30). Prepared ac-
cording to the general procedure and purified by HPLC (2.5%
MeOH/CH2Cl2) to afford 50 mg of 30 (36% yield): mp 186 °C;

2028 J ournal of Medicinal Chemistry, 2000, Vol. 43, No. 10
Corbett et al.
1H NMR (300 MHz, acetone-d6) δ 9.13 (br s, 1H), 8.61 (d, J )
4.8 Hz, 1H), 7.88-7.83 (m, 1H), 7.65 (d, J ) 7.7 Hz, 1H), 7.47-
7.41 (m, 1H), 7.11 (dd, J ) 9.2 Hz, 1H); 19F NMR (282 MHz,
acetone-d6) δ -81.0 (s, 3F), -121.1 (s, 1F); HRMS calcd for
C16H9ClF4N3O [M + H]+ 370.0370, found 370.0355. Anal.
(C16H8ClF4N3O‚0.6CH4O) C, H, N.
3,4-Dih yd r o-6-flu or o-4-[(2-p yr id yl)eth yn yl]-4-(tr iflu o-
r om eth yl)-2(1H)-qu in a zolin on e (31). Prepared according to
the general procedure and purified by HPLC (2.5% MeOH/
CH2Cl2) to afford 65 mg of 31 (45% yield): mp 155 °C; 1H NMR
(300 MHz, acetone-d6) δ 9.02 (br s, 1H), 8.60 (d, J ) 4.0 Hz,
1H), 7.87-7.78 (m, 2H), 7.66 (d, J ) 7.7 Hz, 1H), 7.45-7.41
(m, 2H), 7.26-7.20 (m, 1H), 7.09-7.05 (m, 1H); 19F NMR (282
MHz, acetone-d6) δ -82.4 (s, 3F), -122.9 to -123.0 (m, 1F);
HRMS calcd for C16H10F4N3O [M + H]+ 336.0760, found
336.0742. Anal. (C16H9F4N3O‚0.25H2O) C, H, N.
1H), 6.86-6.81 (m, 1H), 2.72-2.63 (m, 1H), 1.17 (d, J ) 6.6
Hz, 6H); 19F NMR (282 MHz, acetone-d6) δ -83.3 (s, 3F),
-135.7 to -135.9 (m, 1F), -148.0 to -148.1 (m, 1F); HRMS
calcd for C14H12F5N2O [M + H]+ 319.0870, found 319.0864.
Anal. (C14H11F5N2O) C, H, N.
(4R)-5,6-Diflu or o-3,4-d ih yd r o-4-(3-m eth ylbu tyn -1-yl)-4-
(tr iflu or om eth yl)-2(1H)-qu in a zolin on e (38): mp 98 °C;
[R]D ) +4.45° (c ) 0.292, MeOH); 1H NMR (300 MHz,
20
acetone-d6) δ 9.19 (br s, 1H), 7.66 (br s, 1H), 7.44-7.35 (m,
1H), 6.86-6.81 (m, 1H), 2.74-2.60 (m, 1H), 1.17 (d, J ) 7.0
Hz, 6H); 19F NMR (282 MHz, acetone-d6) δ -83.3 (s, 3F),
-135.7 to -135.9 (m, 1F), -148.0 to -148.1 (m, 1F); HRMS
calcd for C14H12F5N2O [M + H]+ 319.0870, found 319.0864.
Anal. (C14H11F5N2O) C, H, N.
The enantiomers of 14 (DPC 961 and 39) were separated
by HPLC using Chiralcel OD, 3% 2-propanol, 5% CH2Cl2, and
92% hexanes with a flow rate of 1.0 mL/min at ambient
temperature. A UV detector set to 250 nm was used and the
first enantiomer to elute was DPC 961. The ee of DPC 961
was 99% and the ee of 39 was 99.4%, as determined by chiral
HPLC analysis.
3,4-Dih yd r o-6-m et h oxy-4-[(2-p yr id yl)et h yn yl]-4-(t r i-
flu or om eth yl)-2(1H)-qu in a zolin on e (32). Prepared accord-
ing to the general procedure and purified by HPLC (2.5%
MeOH/CH2Cl2) to afford 56 mg of 32 (39% yield): mp 97-98
1
°C; H NMR (300 MHz, acetone-d6) δ 8.81 (br s, 1H), 8.61 (d,
J ) 4.8 Hz, 1H), 7.88-7.82 (m, 1H), 7.66 (d, J ) 7.7 Hz, 1H),
7.61 (br s, 1H), 7.46-7.42 (m, 1H), 7.23 (br s, 1H), 7.06-6.97
(m, 2H), 3.79 (s, 3H); 19F NMR (282 MHz, acetone-d6) δ -82.1
(s, 3F); HRMS calcd for C17H13F3N3O2 [M + H]+ 348.0960,
found 348.0956. Anal. (C17H12F3N3O2‚0.25C3H6O) C, H, N.
5,6-Diflu or o-3,4-d ih yd r o-4-(p h en yleth yn yl)-4-(tr iflu o-
r om eth yl)-2(1H)-qu in a zolin on e (33). Prepared according to
the general procedure and purified by HPLC (2.5% MeOH/
CH2Cl2) to afford 92 mg of 33 (65% yield): mp 215-217 °C;
1H NMR (300 MHz, acetone-d6) δ 9.14 (br s, 1H), 7.80 (br s,
1H), 7.57-7.54 (m, 2H), 7.49-7.40 (m, 4H), 6.92-6.87 (m, 1H);
19F NMR (282 MHz, acetone-d6) δ -83.0 (d, J ) 12.9 Hz, 3F),
-136.1 to -136.3 (m, 1F), -147.9 to -148.0 (m, 1F); HRMS
calcd for C17H10F5N2O [M + H]+ 353.0713, found 353.0717.
Anal. (C17H9F5N2O) C, H, N.
(4S)-6-Ch lor o-4-(cyclop r op ylet h yn yl)-3,4-d ih yd r o-4-
(tr iflu or om eth yl)-2(1H)-qu in a zolin on e (DP C 961): mp
180-181 °C; [R]D ) -60.34° (c ) 0.274, MeOH); 1H NMR
20
(300 MHz, acetone-d6) δ 9.01 (br s, 1H), 7.51 (br s, 1H), 7.40
(dd, J ) 8.4, 2.2 Hz, 1H), 7.01 (d, J ) 8.4 Hz, 1H), 1.49-1.41
(m, 1H), 0.93-0.86 (m, 2H), 0.77-0.72 (m, 2H); 19F NMR (282
MHz, acetone-d6) δ -83.0 (s, 3F); HRMS calcd for C14H11
ClF3N2O [M + H]+ 315.0512, found 315.0525. Anal. (C14H10
ClF3N2O), C, H, N.
-
-
(4R)-6-Ch lor o-4-(cyclop r op ylet h yn yl)-3,4-d ih yd r o-4-
(tr iflu or om eth yl)-2(1H)-qu in a zolin on e (39): mp 105-107
20
1
°C; [R]D = +58.33° (c ) 0.288, MeOH); H NMR (300 MHz,
acetone-d6) δ 9.21 (br s, 1H), 7.69 (br s, 1H), 7.52-7.51 (m,
1H), 7.39 (dd, J ) 8.4, 2.6 Hz, 1H), 7.00 (d, J ) 8.4 Hz, 1H),
1.49-1.40 (m, 1H), 0.92-0.86 (m, 2H), 0.77-0.72 (m, 2H); 19
F
6-Ch lor o-3,4-d ih yd r o-4-(p h en yleth yn yl)-4-(tr iflu or om -
eth yl)-2(1H)-qu in a zolin on e (34). Prepared according to the
general procedure and purified by HPLC (2.5% MeOH/CH2-
Cl2) to afford 54 mg of 34 (38% yield): mp 104-107 °C; 1H
NMR (300 MHz, acetone-d6) δ 9.07 (br s, 1H), 7.74 (br s, 1H),
7.67 (br s, 1H), 7.62-7.58 (m, 2H), 7.48-7.40 (m, 4H), 7.08 (d,
J ) 8.4 Hz, 1H); 19F NMR (282 MHz, acetone-d6) δ -82.7 (s,
NMR (282 MHz, acetone-d6) δ -83.0 (s, 3F); HRMS calcd for
C
14H11ClF3N2O [M + H]+ 315.0512, found 315.0500. Anal.
(C14H10ClF3N2O), C, H, N.
The enantiomers of 13 (DPC 963 and 40) were separated
by HPLC using Chiralpak AD, 5% H2O in methanol with a
flow rate of 0.8 mL/min at ambient temperature. A UV detector
set to 250 nm was used, and the first enantiomer to elute was
DPC 963. The ee of DPC 963 was 100% and the ee of 40 was
99%, as determined by chiral HPLC analysis.
3F); HRMS calcd for
C
17H10F5N2O [M]+ 353.0713, found
353.0717. Anal. (C17H10ClF3N20‚0.25H2O) C, H, N.
3,4-Dih yd r o-6-flu or o-4-(p h en yleth yn yl)-4-(tr iflu or om -
eth yl)-2(1H)-qu in a zolin on e (35). Prepared according to the
general procedure and purified by HPLC (2.5% MeOH/CH2-
(4S)-4-(Cyclop r op yleth yn yl)-5,6-d iflu or o-3,4-d ih yd r o-
4-(tr iflu or om eth yl)-2(1H)-qu in a zolin on e (DP C 963): mp
187 °C; [R]D20 = +1.46° (c ) 0.274, MeOH); 1H NMR (300 MHz,
acetone-d6) δ 9.00 (br s, 1H), 7.45-7.35 (m, 2H), 6.84 (dq, J )
9.2, 4.0 Hz, 1H), 1.42-1.35 (m, 1H), 0.90-0.83 (m, 1H), 0.74-
0.69 (m, 1H); 19F NMR (282 MHz, acetone-d6) δ -83.3 (d, J )
12.9 Hz, 3F), -136.0 to -136.2 (m, 1F), -148.1 to -148.3 (m,
1F); HRMS calcd for C14H10F5N2O [M + H]+ 317.0713, found
317.0715. Anal. (C14H9F5N2O) C, H, N.
1
Cl2) to afford 41 mg of 35 (29% yield): mp 107 °C; H NMR
(300 MHz, acetone-d6) δ 9.00 (br s, 1H), 7.69 (br s, 1H), 7.63-
7.59 (m, 2H), 7.50-7.40 (m, 4H), 7.27-7.20 (m, 1H), 7.10-
7.05 (m, 1H); 19F NMR (282 MHz, acetone-d6) δ -82.6 (s, 3F),
-123.0 to -123.1 (m, 1F); HRMS calcd for C17H11F4N2O [M +
H]+ 335.0808, found 335.0821.
3,4-Dih yd r o-6-m et h oxy-4-(p h en ylet h yn yl)-4-(t r iflu o-
r om eth yl)-2(1H)-qu in a zolin on e (36). Prepared according to
the general procedure and purified by HPLC (2.5% MeOH/
CH2Cl2) to afford 34 mg of 36 (24% yield): mp 206-207 °C;
1H NMR (300 MHz, acetone-d6) δ 8.85 (br s, 1H), 7.60-7.57
(m, 3H), 7.49-7.39 (m, 3H), 7.21 (br s, 1H), 7.05-6.96 (m, 2H),
3.79 (s, 3H); 19F NMR (282 MHz, acetone-d6) δ -82.3 (s, 3F);
HRMS calcd for C18H14F3N2O2 [M + H]+ 347.1007, found
347.1015. Anal. (C18H13F3N2O2) C, H, N.
Isola tion of Op tica lly Active Com p ou n d s. The enanti-
omers of 20 (37 and 38) were separated by HPLC using
Chiralpak AD, 5% H2O in methanol with a flow rate of 0.5
mL/min at ambient temperature. A UV detector set to 250 nm
was used, and the first enantiomer to elute was 37. The ee of
37 was 99% and the ee of 38 was 100%, as determined by chiral
HPLC analysis.
(4R)-4-(Cyclopr opyleth yn -1-yl)-5,6-diflu or o-3,4-dih ydr o-
4-(tr iflu or om eth yl)-2(1H)-qu in a zolin on e (40): mp 188-
189 °C; [R]D20 = -1.45° (c ) 0.278, MeOH); 1H NMR (300 MHz,
acetone-d6) δ 9.04 (br s, 1H), 7.50 (br s, 1H), 7.44-7.35 (m,
1H), 6.86-6.81 (m, 1H), 1.44-1.35 (m, 1H), 0.90-0.83 (m, 2H),
0.74-0.69 (m, 2H); 19F NMR (282 MHz, acetone-d6) δ -83.3
(d, J ) 12.9 Hz, 3F), -136.0 to -136.2 (m, 1F), -148.1 to
-148.2 (m, 1F); HRMS calcd for C14H10F5N2O [M + H]+
317.0713, found 317.0704. Anal. (C14H9F5N2O) C, H, N.
Gen er a l P r oced u r e for Alk yn e Red u ction . To a -78 °C
solution of either DPC 961 or DPC 963 in anhydrous THF (0.5
M) containing 1,2-dichlorobenzene (2 equiv) was added drop-
wise via an addition funnel a 1 M solution in THF of lithium
aluminum hydride (LAH) (2 mol equiv). Following the addition
of the LAH, the cooling bath was removed and the mixture
was allowed to reach room temperature. The mixture was
stirred at room temperature overnight, and the reaction was
monitored for completion by analyzing for the presence of the
CF3 from the starting material, as determined by 19F NMR. If
necessary, more LAH (0.4 mol equiv) was added and the
(4S)-5,6-Diflu or o-3,4-d ih yd r o-4-(3-m eth ylbu tyn -1-yl)-4-
(tr iflu or om eth yl)-2(1H)-qu in a zolin on e (37): mp 155 °C;
[R]D ) -2.14° (c ) 0.280, MeOH); 1H NMR (300 MHz,
20
acetone-d6) δ 9.15 (br s, 1H), 7.62 (br s, 1H), 7.44-7.35 (m,

Inhibition of Mutant Variants of HIV-1
J ournal of Medicinal Chemistry, 2000, Vol. 43, No. 10 2029
mixture monitored for completion as previously described.
Upon completion of the reaction, determined by the absence
of the starting material’s CF3 signal in 19F NMR, the mixture
was cooled to 0 °C and carefully quenched with 20% aqueous
KHSO4. The solids were removed by vacuum filtration and
washed with EtOAc. The organic extract was separated from
the filtrate. The aqueous phase was back-extracted with
EtOAc, and the combined organic extracts were washed with
saturated aqueous NaCl, dried over MgSO4, filtered, and
concentrated to afford a yellow oil. The material was then
purified flash chromatography and/or crystallization.
then compared and reported as the fold increase in IC90
observed (PB shift).
Refer en ces
(1) Kahn, J . O.; Walker, B. D. Acute Human Immunodeficiency
Virus Type 1 Infection. New Engl. J . Med. 1998, 339, 33-39.
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T.; J effrey, S.; Cordova, B. C.; Klabe, R. M.; Diamond, S.;
Rodgers, J . D.; Trainor, G. L.; Anderson, P. S. Data on DPC 961
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(4S)-4-[(1E)-2-Cyclop r op yleth en yl)-5,6-d iflu or o-3,4-d i-
h ydr o-4-(tr iflu or om eth yl)-2(1H)-qu in azolin on e (DP C 082).
Prepared by reduction of DPC 963 according to the general
procedure and purified by flash chromatography (30% EtOAc/
hexanes) followed by crystallization from hexanes to afford a
white solid. This material was dried at 75 °C/0.5 mmHg
overnight to give 13.65 g of DPC 082 as a white powder (55%
yield): mp 188.7-189.4 °C; [R]D20 = +72.77° (c ) 0.382, MeOH);
1H NMR (300 MHz, acetone-d6) δ 9.03 (br s, 1H), 7.37-7.28
(m, 1H), 6.90 (br s, 1H), 6.90-6.79 (m, 1H), 6.27 (dd, J ) 15,
7.7 Hz, 1H), 5.67 (dd, J ) 15, 9.5 Hz, 1H), 1.66-1.54 (m, 1H),
0.82-0.71 (m, 2H), 0.51-0.40 (m, 2H); 19F NMR (282 MHz,
acetone-d6) δ -82.6 to -82.8 (m, 3F), -135.0 to -135.2 (m,
1F), -148.5 to -148.6 (m, 1F); HRMS calcd for C14H12F5N2O
[M + H]+ 319.0870, found 319.0878. Anal. (C14H11F5N2O) C,
H, N.
(3) A preliminary report of this work has appeared: Corbett, J . W.;
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(4S)-6-Ch lor o-4-[(1E)-cyclop r op yleth en yl)-3,4-d ih yd r o-
4-(tr iflu or om eth yl)-2(1H)-qu in a zolin on e (DP C 083). Pre-
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mmHg overnight to give 22.8 g of DPC 083 as a white powder
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20
(91% yield): mp 167-168 °C; [R]D = -6.81° (c ) 0.382,
MeOH); 1H NMR (300 MHz, acetone-d6) δ 8.94 (br s, 1H), 7.40
(s, 1H), 7.32 (dd, J ) 8.4, 2.2 Hz, 1H), 6.98 (d, J ) 8.4 Hz,
1H), 6.88 (br s, 1H), 6.25 (d, J ) 15 Hz, 1H), 5.60 (dd, J ) 15,
9.5 Hz, 1H), 1.68-1.56 (m, 1H), 0.83-0.71 (m, 2H), 0.53-0.41
(m, 2H); 19F NMR (282 MHz, acetone-d6) δ -81.7 (s, 3F);
HRMS calcd for C14H13ClF3N2O [M + H]+ 317.0669, found
317.0659. Anal. (C14H12ClF3N2O) C, H, N.
Biologica l Assa ys. The ability of NNRTI analogues to
inhibit the HIV-1 reverse transcriptase was assessed using
purified, recombinant, radiolabeled dTTP and a poly r(A)‚oligo
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analogues to inhibit HIV replication in tissue culture was
assessed using several assay systems. The yield of infectious
virus produced in 3-day acute infections by laboratory strains
or clinical isolates of HIV-1 in MT-2 cells or viruses previously
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progeny virions as previously described.24 The antiviral activity
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capture and alkaline phosphatase-derivatized reporter oligo-
nucleotides.19 In a third system, the effects of analogues on
the replication of recombinant viruses in the HXB2 or NL4-3
background was determined by measurement of viral p24
antigen from MT-4 infections as previously described.3 In all
assays, the concentration of compound which reduced the
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measured parameter by 90% was designated the IC90
.
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antiviral efficacy, a functional assay and, in some cases,
physical measurement of the extent of binding to serum
proteins were used. For the functional assay, in vitro antiviral
assays were conducted in the presence or absence of the two
major components of human plasma, namely human serum
albumin (HSA) and alpha-1-acid glycoprotein (AAG) (antiviral
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mg/mL HSA and 1 mg/mL AAG, concentrations of serum
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2030 J ournal of Medicinal Chemistry, 2000, Vol. 43, No. 10
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