Novel non-nucleoside inhibitors of human immunodeficiency virus type 1 reverse transcriptase. 6. 2-Indol-3-yl- and 2-azaindol-3-yl- dipyridodiazepinones

Article abstract of DOI:10.1021/jm960837y

Modification of the non-nucleoside inhibitor of HIV-1 reverse transcriptase nevirapine (Viramune) by incorporation of a 2-indolyl substituent confers activity against several mutant forms of the enzyme.

Full text of DOI:10.1021/jm960837y

2
430
J . Med. Chem. 1997, 40, 2430-2433
Novel Non -Nu cleosid e In h ibitor s of Hu m a n Im m u n od eficien cy Vir u s Typ e 1
Rever se Tr a n scr ip ta se. 6. 2-In d ol-3-yl- a n d 2-Aza in d ol-3-yl-
d ip yr id od ia zep in on es1
†
Terence A. Kelly,* Daniel W. McNeil, J anice M. Rose, Eva David, Cheng-Kon Shih, and Peter M. Grob
Research and Development Center, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury Road, P.O. Box 368,
Ridgefield, Connecticut 06877
X
Received December 10, 1996
Modification of the non-nucleoside inhibitor of HIV-1 reverse transcriptase nevirapine
(
Viramune) by incorporation of a 2-indolyl substituent confers activity against several mutant
forms of the enzyme.
In tr od u ction
Sch em e 1. Representative Synthesis of 2-Indolyl
Derivatives
2
Nevirapine (Viramune, 1) represents the first mem-
ber of the non-nucleoside class of inhibitors of reverse
transcriptase (RT) to receive approval for the treatment
of human immunodeficiency virus (HIV) infections.
This drug binds to an allosteric region on the protein
and induces conformational changes that halt the poly-
merase activity of the enzyme.3 In clinical settings,
mutations to wild-type RT have been observed that are
resistant to nevirapine and thus require that this class
4
of inhibitor be used in combination with other drugs.
Recently, Proudfoot et al. reported that incorporation
of aryl substituents at the 2-position of the dipyridodi-
azepinone ring system to generate structures such as 2
can confer activity against mutant forms of the enzyme
including the clinically important Y181C.5 The current
work expands on this theme by exploring the effect of
changing the 2-pyrrolyl substituent to larger, indole-
based rings on the molecules’ potency against an
expanded panel of RT mutants.
a
Reagents: (i) ICl, pyridine, 0 °C (generates 3-iodo compound)
or Br2, CCl4, i-PrNEt2, 0 °C (generates 3-bromo compound); (ii)
Boc2O, DMAP, dioxane; (iii) (a) n-BuLi, TMEDA, THF, -78 °C,
b) SnBu3Cl; (iv) PdCl2(PPh3)2, LiCl, DMF, 110 °C.
(
6
4% isolated yield. All of the other 2-indol-3-yl com-
pounds were produced in a similar manner, but it should
be noted that the isolated yields of the cross-coupling
reactions of the azaindol-3-yl derivatives (7d -g) were
very low (5-15%) due largely to difficulties in purifica-
tion.
Resu lts a n d Discu ssion
Compounds were first screened against purified wild-
type HIV-1-RT as well as the Y181C mutant and the
Y188L mutant. IC50’s were calculated on compounds
that showed the potential for generating complete dose-
response curves (i.e. compounds with approximately
50% inhibition at a concentration of 1 µM). The results
of testing are shown in Table 1. The details of the
Ch em istr y
A general synthesis of the 2-indol-3-yl derivatives is
outlined in Scheme 1 for the synthesis of the unsubsti-
tuted compound 7a . Halogenation of indole (3a ) with
6
ICl in pyridine produced 3-iodoindole, which was im-
3
mediately converted to its N-Boc derivative (4a ) by
treatment with Boc2O in the presence of DMAP. (For
compounds 3d ,7 3e, and 3f,7 we proceeded via the
enzyme assays which measure the incorporation of [ H]-
dGTP into a poly(rC):oligo(dG) template have been
7
2b
published previously. When a compound showed an
8
previously reported bromination rather than iodination
IC50 of less then 1 µM against all three enzymes, it was
then screened against a panel of four other mutants of
HIV-1-RT derived from clinical isolates. These tests
were performed with partially purified cell lysates. The
secondary evaluation was assessed against the following
mutants: K103N, V106A, G190A, and P236L.10 These
results are shown in Table 2.
Initial screening of the unsubstituted 2-indol-3-yl
derivative 7a demonstrated that the region of the RT
enzymes that binds the 2-aryl substituents is large
enough to tolerate the increase in size observed in going
procedure to generate the known 3-bromo derivatives.)
Lithium-halogen exchange on derivative 4a induced by
the reaction with n-BuLi in the presence of TMEDA at
-
78 °C generated an anion which was trapped with Bu3-
SnCl to give 5a . The organostannane was then coupled
5
to the triflate 6 in the presence of Pd(Ph3P)2Cl2 and
LiCl in DMF at 110 °C.9 This generated product 7a in
†
Deceased August 19, 1995.
Abstract published in Advance ACS Abstracts, J une 15, 1997.
X
S0022-2623(96)00837-0 CCC: $14.00 © 1997 American Chemical Society

Notes
J ournal of Medicinal Chemistry, 1997, Vol. 40, No. 15 2431
Ta ble 1. Activity of 2-Indol-3-yldipyridodiazepinones (7) vs WT
and Mutant HIV-1 RT
Proceeding sequentially around the ring, the 4-aza-
indol-3-yl compound (7d ) had only weak activity in the
primary screening assays. The next compound, the
a
5
-azaindol-3-yl derivative (7e), had good potency against
both the WT and Y181C enzymes but showed only 3%
inhibition of Y188L at the 1 µM screening concentration.
The 6-azaindol-3-yl compound (7f) regained activity
against all three of the primary mutants but was 4-fold
less potent than the starting indol-3-yl compound (7a )
against the Y188L mutant. However, against some of
the secondary panel, this derivative (7f) was exception-
ally potent, in particular against both the K103N (32
nM) and P236L (1 nM) mutants. The 7-azaindol-3-yl
compound 7g had good activity against both the WT and
Y181C enzymes, but its potency vs the Y188L mutant
was over a log weaker than the potency of 7a . We are
currently exploring QSAR studies to explain the ob-
served differences in the profile of these compounds.
It should be noted that these compounds are not being
pursued due to unacceptable levels of cytotoxicity in the
MTT cellular assay (for example, compound 7f was toxic
to half of the cells at concentrations below 25 µM). The
source of this unwanted activity has not been pin-
pointed, but it unfortunately precludes the evaluation
of these compounds in cell-passaging experiments which
would allow for the selection of resistant mutants.
Regardless, the results from this series demonstrates
the possibility of producing nevirapine derivatives with
broad spectrum activity against a variety of HIV reverse
transcriptase enzymes. The hypothesis that such activ-
ity can lead to more effective antivirals in vitro is
a
nd ) not determined.
Ta ble 2. Secondary Evaluation of 2-Indol-3-yldipyrido-
diazepinones
IC50 (nM)
5,11
supported by previous work.
compd
K103N
V106A
G190A
P236L
Con clu sion s
2
50
97
935
32
1000
49
3090
228
320
12
600
19
130
79
404
<1
7
7
7
a
b
f
It has been proposed that the administration of
compounds that have complimentary activity against
various forms of RT could be clinically useful in the
treatment of this viral infection. Clearly a simpler
approach would be to develop reagents that have broad
spectrum activity against the same targets. The series
of compounds presented in this work demonstrates the
possibility of producing derivatives of nevirapine that
have activity against several clinically relevant forms
of HIV-1 reverse transcriptase.
from a pyrrole to an indole moiety (2 vs 7a , Table 1).
The IC50’s of 7a were 28, 28, and 90 nM against WT,
Y181C, and Y188L, respectively, vs 33, 50, and 100 nM
for compound 2 against the same series. More signifi-
cantly, as compared to compound 2, compound 7a ex-
hibits dramatically improved potency against two of the
four secondary mutant enzymes (V106A (49 vs 1000 nM)
and G190A (12 vs 320 nM)) while still retaining activity
against the K103N and P236L mutants (Table 2).
Exp er im en ta l Section
Gen er a l Exp er im en ta l. For general experimental details,
see ref 2b. For details on the construction of mutant HIV-1
RT clones and the expression of the enzymes, see ref 10 and
references therein. Starting materials 3a , 3b, 3c, and 3g are
commercially available (Aldrich). Starting materials 3d , 3e,
and 3f were prepared and brominated in accord with previ-
ously reported literature procedures.
Rever se Tr a n scr ip ta se Assa y. Composition of stock and
reaction mixture:
These results encouraged us to explore this region
more thoroughly. The first two compounds, 7b and 7c,
which were made from commercially available indoles,
contained the 5-methoxy- and 5-fluoroindolyl substitu-
ent. These derivatives both lost considerable potency
against the wild-type enzyme when compared with the
unsubstituted compound 7a (200 and 706 nM vs 28 nM,
respectively). Lower potency was also observed when
gauged against the two primary mutant enzymes. For
compound 7b , results shown in Table 2 demonstrate
that this trend continued across all of the tested
mutants.
7
8
2
.4× mix
final assay
concn
stock reagent
M Tris pH 7.8
M dithiothrietol
M NaCl
1 M MgCl2
poly r(C)500/oligo d(G)10] (27:1)
concn
1
1
1
120 mM
9.6 mM
144 mM
4.8 mM
11.6 µg/mL
1.1 µM
50 mM
4 mM
60 mM
2.0 mM
4.8 µg/mL
0.45 µM
0.02%
At this point in the project we observed that the
indole-based compounds were increasingly less soluble
than the pyrrole presumably due to an increase in
lipophilicity. Consequently, we explored the azaindole
series 7d -g to see if it was possible to retain the potency
of compound 7a while possibly alleviating some of the
solubility concerns.
[
3
[
H]dGTP (93 µM, 10.7 Ci/mmol)
Chaps
RT enzyme
test compound
0.63 nM
10 µg/mL

2
432 J ournal of Medicinal Chemistry, 1997, Vol. 40, No. 15
Notes
This enzyme assay has been adapted to a 96-well microtiter
7.00 (dd, J ) 5, 1 Hz, 1 H), 7.69 (s, 1 H), 8.01 (d, J ) 5 Hz, 1
plate system and has been previously described.12 Tris buffer
H); MS (CI) m/ z 374 (MH , 65), 318 (100).
+
(
50 mM, pH 7.8), vehicle (solvent diluted to match the
compound dilution), or compounds in vehicle are dispensed into
6-well microtiter plates (10 µL/well; 3 wells/compound). The
1-(ter t-Bu tyloxyca r bon yl)-5-flu or o-3-iod oin d ole (4c).
1
Two-step yield from 5-fluoroindole (3c): 97%; H NMR (CDCl
3
)
9
δ 1.66 (s, 9 H), 6.99-7.10 (m, 2 H), 7.72 (s, 1 H), 8.08 (m, 1 H).
HIV-1 RT enzyme is thawed, diluted in 50 mM Tris, pH 7.8,
containing 0.05% Chaps to give 1.5 nM enzyme, and 25 µL
are dispensed per well. Ten microliters of 0.5 M EDTA are
added to the first three wells of the microtiter plate. EDTA
chelates the Mg present and prevents reverse transcription.
This group serves as background polymerization which is
subtracted from all other groups. Twenty-five microliters of
the 2.4× reaction mixture are added to all wells, and the assay
is allowed to incubate at room temperature for 30 min. The
assay is terminated by precipitating the DNA in each well with
4-Aza -3-b r om o-1-(ter t-b u t yloxyca r b on yl)in d ole (4d ).
1
Yield from 4-aza-3-bromoindole: 76%; H NMR (CDCl ) δ 1.67
3
(s, 9 H), 7.28 (dd, J ) 8, 5 Hz, 1 H), 7.89 (s, 1 H), 8.33 (d, J )
8 Hz, 1 H), 8.59 (d, J ) 5 Hz, 1 H).
2
+
5-Aza -3-b r om o-1-(ter t-b u t yloxyca r b on yl)in d ole (4e).
1
Yield from 5-aza-3-bromoindole: 42%; H NMR (CDCl ) δ 1.67
3
(s, 9 H), 7.64 (s, 1 H), 7.97 (d, J ) 6 Hz, 1 H), 8.53 (d, J ) 6
Hz, 1 H), 8.83 (s, 1 H).
6-Aza -3-b r om o-1-(ter t-b u t yloxyca r b on yl)in d ole (4f).
1
Yield from 6-aza-3-bromoindole: 42%; H NMR (CDCl ) δ 1.69
3
6
0 µL of sodium pyrophosphate (2% w/v) in 10% trichloracetic
(s, 9 H), 7.45 (d, J ) 5 Hz, 1 H), 7.99 (s, 1 H), 8.53 (bs, 1 H),
acid (TCA, 10% w/v). The microtiter plate is incubated for 15
min at 4 °C, and the precipitate is harvested onto no. 30 glass
fiber paper (Schleicher & Schuell) using a Tomtech 96-well
harvester. The filters are then dried, placed into plastic bags
with Betaplate scintillation cocktail (Pharmacia/LKB), and
counted in the Betaplate counter (Pharmacia/LKB).
9.45 (bs, 1 H).
7
-Aza-1-(ter t-bu tyloxycar bon yl)-3-iodoin dole (4g). Two-
1
step yield from 7-azaindole (3g): 64%; H NMR (CDCl
s, 9 H), 7.28 (dd, J ) 8, 5 Hz, 1 H), 7.72 (dd, J ) 8, 1 Hz, 1 H),
.80 (s, 1 H), 8.49 (dd, J ) 5, 1 Hz, 1 H).
Gen er a l P r oced u r e for th e Syn th esis of Com p ou n d s
3
) δ 1.70
(
7
MTT Assa y. The MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-
diphenyltetrazolium bromide] assay is based on cleavage of
tetrazolium bromide by metabolically active cells, resulting in
a highly quantitative blue color. This assay has been previ-
5. Compounds of structure 4 (1.47 mmol) were dissolved in
40 mL of THF and cooled to -78 °C under an inert atmosphere.
A solution of n-BuLi (2.5 M; 1.50 mmol) was introduced over
a period of time such that the reaction temperature did not
rise more than 5 °C. After addition was complete, the mixture
1
3a
ously described but has been optimized for the purposes of
the testing reported herein.
was stirred for 15 min and then treated with Bu SnCl (1.66
3
1
3b
The C8166-45 cell line,
a fusion of umbilical blood
mmol). The bath was then removed, and the solution was
allowed to warm to room temperature over 2 h. The mixture
lymphocytes and T-cells from leukemia-lymphoma patients
grown in RPMI 1640 supplemented with 10% fetal bovine
serum, is used as the target cell line in the assay. Cells (100
was diluted with 150 mL of hexane and washed with H O and
2
a saturated NaCl solution. The organics were dried over
MgSO4 and concentrated. In general the stannanes were
difficult to purify and could be used without further purifica-
tion. In cases where they were purified, chromatography over
µL) are plated in microtest plate wells at a concentration of
5
1
0
cells/mL in the presence of varying concentrations of
inhibitor in 50 µL of RPMI 1640. The cells are incubated at
3
7 °C in a humidified CO incubator. Five days later, 20 µL
2
neutral alumina (Fischer A950-500 deactivated with 5% H O)
2
using 5% EtOAc in hexanes as the eluant usually sufficed.
When noted, it was necessary to purify the compounds over a
C18 column.
of MTT (5 mg/mL in RPMI 1640, warmed, 0.2 µm filtered, and
stored at 4 °C) is added to each well. After 4 h additional
incubation at 37 °C, 60 µL of 0.01 N HCl in 10% Triton X-100
is added to each well and thoroughly mixed to aid the
solubilization of the crystals. A bunsen burner is briefly run
across the top of the plate to disrupt bubbles, and the plate is
read at 600 nm after 10 min. The average blank reading is
subtracted from all wells, and inhibition is calculated.
Gen er a l P r oced u r e for th e Syn th esis of Com p ou n d s
1-(t er t -Bu t yloxyca r b on yl)-3-(t r i-n -b u t ylst a n n yl)in -
1
d ole (5a ): yield 14%; H NMR (CDCl ) δ 0.90 (t, J ) 7 Hz, 9
3
H), 1.11 (m, 6 H), 1.35 (m, 6 H), 1.60 (m, 6 H), 1.81 (s, 9 H),
7.18-7.40 (m, 2 H), 7.45-7.55 (m, 2 H), 8.10 (d, J ) 5 Hz, 1
H).
1-(ter t-Bu tyloxycar bon yl)-5-m eth oxy-3-(tr i-n -bu tylstan -
1
4
. A. 3-Iodo Derivatives. The indole compound 3 (10 mmol)
was dissolved in 10 mL of pyridine and cooled in an ice bath.
A solution of ICl (1 M in CH
Cl ; 11 mmol) was added over 5
n yl)in d ole (5b): crude material; H NMR (CDCl ) δ 0.95 (m,
3
9 H), 1.15 (m, 6 H), 1.45-1.90 (m, 21 H), 3.92 (s, 3 H), 6.80-
7.05 (m, 2 H), 7.50-7.65 (m, 1 H), 8.00 (m, 1 H).
2
2
min. After 15 min the cooling bath was removed, and after
another 30 min the solution was diluted with 100 mL of EtOAc.
The organic solution was washed sequentially with 1 N HCl
and 1 N NaOH, dried over MgSO , and concentrated to give a
4
residue which was immediately protected as its Boc derivative.
1-(ter t-Bu tyloxyca r bon yl)-5-flu or o-3-(tr i-n -bu tylsta n -
1
n yl)in d ole (5c): purified over C ; yield 56%; H NMR (CDCl )
1
8
3
δ 0.89 (t, J ) 7 Hz, 9 H), 1.16 (m, 6 H), 1.34 (m, 6 H), 1.68 (m,
6 H), 1.70 (s, 9 H), 7.02 (dt, J ) 7, 1 Hz, 1 H), 7.12 (dt, J ) 7,
1 Hz, 1 H), 7.50 (s, 1 H), 8.05 (m, 1 H).
B. 3-Br om o Der iva tives. The indole compound 3 (2.29
4-Aza -1-(ter t-bu tyloxyca r bon yl)-3-(tr i-n -bu tylsta n n yl)-
in d ole (5d ): yield 18% (approximately 50% pure); H NMR
1
mmol) was dissolved in 5 mL of CHCl
bath. Bromine (4.85 mmol) was dissolved in 5 mL of CCl
3
and cooled in an ice
and
4
(major component, CDCl ) δ 0.88 (m, 9 H), 1.1-1.8 (m, 27 H),
3
added dropwise to the reaction mixture until no compound 3
was observed by TLC. The mixture was diluted with 20 mL
7.09 (m, 1 H), 7.70 (bs, 1 H), 8.20 (broad d, 1 H), 8.45 (m, 1 H).
5-Aza -1-(ter t-bu tyloxyca r bon yl)-3-(tr i-n -bu tylsta n n yl)-
1
of CH
2
Cl
2
and extracted into 2 N HCl. The HCl extracts were
in d ole (5e): yield 14%; H NMR (CDCl ) δ 0.89 (t, J ) 7 Hz,
3
neutralized with concentrated NaOH, and the resulting pre-
cipitate was collected, dried, and protected immediately as its
Boc derivative.
Boc P r otection of 3-Ha loin d oles (4). The 3-haloindole
compounds from above were dissolved in dioxane (50 mL) and
9 H), 1.21 (m, 6 H), 1.25-1.70 (m, 12 H), 1.74 (s, 9 H), 7.47 (m
1 H), 7.95 (broad d, 1 H), 8.44 (d, J ) 6 Hz, 1 H), 8.80 (s, 1 H).
6-Aza -1-(ter t-bu tyloxyca r bon yl)-3-(tr i-n -bu tylsta n n yl)-
1
in d ole (5f): yield 20%; H NMR (CDCl ) δ 0.91 (t, J ) 7 Hz,
3
9 H), 1.15-1.70 (m, 18 H), 1.78 (s, 9 H), 7.40 (d, J ) 6 Hz, 1
H), 7.61 (m, 1 H), 8.38 (d, J ) 6 Hz, 1 H), 9.35 (s, 1 H).
7-Aza -1-(ter t-bu tyloxyca r bon yl)-3-(tr i-n -bu tylsta n n yl)-
treated with Boc
the mixture was stirred at room temperature overnight, excess
Boc O was destroyed by the addition of 1 mL of N,N-
dimethylethylenediamine. The solution was then washed with
.1 N HCl and saturated NaCl, dried over MgSO , and
2
O (1.1 equiv) and DMAP (0.1 equiv). After
1
2
in d ole (5g): yield 19%; H NMR (CDCl ) δ 0.88 (t, J ) 7 Hz,
3
9 H), 1.20 (m, 6 H), 1.20-1.65 (m, 12 H), 1.68 (s, 9 H), 7.12
(dd, J ) 8, 5 Hz, 1 H), 7.51, (s, 1 H), 7.75 (dd, J ) 8, 1 Hz, 1
H), 8.51 (dd, J ) 5, 1 Hz, 1 H).
0
4
concentrated. Flash chromatography (5% EtOAc:hexanes)
over silica gel produced the desired products.
Gen er a l P r oced u r e for th e Syn th esis of Com p ou n d s
7. Organostannane 5 (0.438 mmol) was added to a DMF (2.5
mL) solution containing compound 6 (0.266 mmol), Pd(Cl)2-
1
-(ter t-Bu tyloxyca r bon yl)-3-iod oin d ole (4a ). Two-step
1
yield from indole (3a ): 92%; H NMR (CDCl
.2-7.41 (m, 3 H), 7.72 (s, 1 H), 8.15 (d, J ) 5 Hz, 1 H).
-(ter t-Bu tyloxycar bon yl)-3-iodo-5-m eth oxyin dole (4b).
Two-step yield from 5-methoxyindole (3b): 70%; 1H NMR
CDCl ) δ 1.63 (s, 9 H), 3.89 (s, 3 H), 6.83 (d, J ) 1 Hz, 1 H),
3
) δ 1.69 (s, 9 H),
7
(Ph P)2 (0.02 mmol), and LiCl (1.49 mmol) under an argon
3
1
atmosphere. The mixture was then heated at 110 °C over-
night. Upon cooling, the solution was partitioned between
EtOAc and H O. After the EtOAc layer was dried (MgSO )
2 4
(
3

Notes
J ournal of Medicinal Chemistry, 1997, Vol. 40, No. 15 2433
and concentrated, the residue was chromatographed (1:1
EtOAc:hexanes) to yield the desired product. This material
Refer en ces
(
1) For previous paper in this series, see: Kelly, T. A.; Proudfoot,
J . R.; McNeil, D. W.; Patel, U. R.; David, E.; Hargrave, K. D.;
Grob, P. M.; Cardozo, M.; Agarwal, A.; Adams, J . Novel Non-
Nucleoside Inhibitors of Human Immunodeficiency Virus Type
1 Reverse Transcriptase. 5. Structure-Activity Relationships of
was recrystallized from CH
,11-Dih yd r o-11-et h yl-2-in d ol-3-yl-5-m et h yl-6H -d ip y-
r id o[3,2-b:2′,3′-e][1,4]d ia zep in -6-on e (7a ): yield 64%; mp
3
CN.
5
1
2
(
7
1
3
41-241.5 °C; H NMR (CDCl ) δ 1.31 (t, J ) 6 Hz, 3 H), 3.52
3
4
-Substituted and 2,4-Disubstituted Analogs of Nevirapine. J .
s, 3 H), 4.39 (q, J ) 6 Hz, 2 H), 7.00 (dd, J ) 8, 5 Hz, 1 H),
Med. Chem. 1995, 38, 4839-47.
.21 (m, 2 H), 7.42 (m, 1 H), 7.51 (m, 2 H), 7.79 (d, J ) 1 Hz,
(
2) (a) Merluzzi, V. J .; Hargrave, K. D.; Labadia, M.; Grozinger, K.;
Skoog, M.; Wu, J . C.; Shih, C.-K.; Eckner, K.; Hattox, S.; Adams,
J .; Rosenthal, A. S.; Faanes, R.; Eckner, R. J .; Koup, R. A.;
Sullivan, J . L. Inhibition of HIV-1 Replication by a Non-
Nucleoside Reverse Transcriptase Inhibitor. Science 1990, 250,
1411-3. (b) Hargrave, K. D.; Proudfoot, J . R.; Grozinger, E.;
Kapadia, S. R.; Patel, U. R.; Fuchs, V. U.; Mauldin, S. C.; Vitous,
J .; Behnke, M. L.; Klunder, J . M.; Pal, K.; Skiles, J . W.; McNeil,
D. W.; Rose, J . M.; Chow, G. C.; Skoog, M. T.; Wu, J . C.; Schmidt,
G.; Engel, W.; Eberlein, W. G.; Saboe, T. D.; Campbell, S. J .;
Rosenthal, A. S.; Adams, J . Novel Non-Nucleoside Inhibitors of
HIV-1 Reverse Transcriptase. 1. Tricyclic Pyridobenzo- and
Dipyridodiazepinones. J . Med. Chem. 1991, 34, 2231-41.
3) (a) Kohlstaedt, L. A.; Wang, J .; Friedman, J . M.; Rice, P. A.;
Steitz, T. A. Crystal Structure at 3.5A Resolution of HIV-1
Reverse Transcriptase Complexed with an Inhibitor. Science
1992, 256, 1783-90. (b) Smerdon, S. J .; J ager, J .; Wang, J .;
Kohlstaedt, L. A.; Friedman, J . M.; Rice, P. A.; Steitz, T. A.
Structure of the Binding Site for Nonnucleoside Inhibitors of
the Reverse Transcriptase of Human Immunodeficiency Virus
Type 1. Proc. Natl. Acad. Sci. U.S.A. 1994, 91, 3911-5. (c)
Esnouf, R.; Ren, J .; Ross, C.; J ones, Y.; Stammers, D.; Stuart,
D. Mechanism of inhibition of HIV-1 reverse transcriptase by
non-nucleoside inhibitors. Struct. Biol. 1995, 2, 303-8.
H), 8.17 (dd, J ) 8, 2 Hz, 1 H), 8.49 (m, 3 H); MS (CI) m/ z
+
70 (MH ). Anal. Calcd for C22
19 5
H N O: C, H, N.
5,11-Dih yd r o-11-eth yl-2-(5-m eth oxyin d ol-3-yl)-5-m eth -
yl-6H-d ip yr id o[3,2-b:2′,3′-e][1,4]d ia zep in -6-on e (7b): yield
1
2
7%; mp 234.5-235.5 °C; H NMR (CDCl
3
) δ 1.31 (t, J ) 6
Hz, 3 H), 3.51 (s, 3 H), 3.99 (s, 3 H), 4.42 (q, J ) 6 Hz, 2 H),
6
.93 (dd, J ) 8, 1 Hz, 1 H), 6.99 (dd, J ) 8, 5 Hz, 1 H), 7.21 (d,
J ) 8 Hz, 1 H), 7.42 (m, 2 H), 7.68 (d, J ) 1 Hz, 1 H), 7.96 (AB
q, 2 H), 8.29 (broad s, 1 H), 8.38 (dd, J ) 8, 2 Hz, 1 H); MS
+
(
CI) m/ z 400 (MH ). Anal. Calcd for C23
H
21
N
5
O
2
: H, N; C:
calcd 69.16, found 68.72.
,11-Dih yd r o-11-eth yl-2-(5-flu or oin d ol-3-yl)-5-m eth yl-
H-d ip yr id o[3,2-b:2′,3′-e][1,4]d ia zep in -6-on e (7c): yield
(
5
6
5
1
7%; mp 234-235 °C; H NMR (CDCl ) δ 1.35 (t, J ) 6 Hz, 3
3
H), 3.55 (s, 3 H), 4.38 (q, J ) 6 Hz, 2 H), 6.99 (m, 2 H), 7.21
(dd, J ) 8, 5 Hz, 1 H), 7.45 (AB q, 2 H), 7.77 (d, J ) 1 Hz, 1
+
H), 8.10 (m, 2 H), 8.40 (m, 2 H); MS (CI) m/ z 388 (MH ). Anal.
Calcd for C22 O: C, H, N.
-(4-Aza in d ol-3-yl)-5,11-d ih yd r o-11-eth yl-5-m eth yl-6H-
d ip yr id o[3,2-b:2′,3′-e][1,4]d ia zep in -6-on e (7d ): yield 5%;
H
18FN
5
2
1
(4) (a) Richman, D.; Havlir, D.; Corbeil, J .; Looney, D.; Ignacio, C.;
Spector, S. A.; Sullivan, J .; Cheeseman, S.; Barringer, K.;
Pauletti, D.; Shih, C.-K.; Myers, M.; Griffin, J . Nevirapine
Resistance Mutations of Human Immunodeficiency Virus Type
mp >140 °C dec; H NMR (CDCl
.58 (s, 3 H), 4.35 (q, J ) 6 Hz, 2 H), 7.05 (dd, J ) 8, 5 Hz, 1
H), 7.2-7.4 (m, 2 H), 7.59 (AB q, 2 H), 7.82 (d, J ) 8 Hz, 1 H),
.12 (dd, J ) 8, 2 Hz, 1 H), 8.47 (m, 2 H), 9.45 (broad s, 1 H);
3
) δ 1.35 (t, J ) 6 Hz, 3 H),
3
8
1
Selected During Therapy. J . Virol. 1994, 68, 1660-6. (b)
+
MS (CI) m/ z 371 (MH ); HRMS calcd for
71.162 034, found 371.162 51.
-(5-Aza in d ol-3-yl)-5,11-d ih yd r o-11-eth yl-5-m eth yl-6H-
d ip yr id o[3,2-b:2′,3′-e][1,4]d ia zep in -6-on e (7e): yield 11%;
C
21
H
19
N
6
O
Murphy, R. L.; Montaner, J . Nevirapine: review of its
a
3
development, pharmacological profile and potential for clinical
use. Exp. Opin. Invest. Drugs 1996, 5, 1183-99.
2
(
5) Proudfoot, J . R.; Hargrave, K. D.; Kapadia, S. R.; Patel, U. R.;
Grozinger, K. G.; McNeil, D. W.; Cullen, E.; Cardozo, M.; Tong,
L.; Kelly, T. A.; Mauldin, S. C.; Fuchs, V. U.; Vitous, J .; West,
M.; Klunder, J .; Raghavan, P.; Skiles, J . W.; Mui, P.; Rose, J .;
David, E.; Richmond, D.; Sullivan, J . L.; Farina, V.; Shih, C.-
K.; Grob, P.; Adams, J . Novel Non-Nucleoside Inhibitors of HIV-1
Reverse Transcriptase. 4. 2-Substituted Dipyridodiazepinones
are Potent Inhibitors of both Wild Type and Cysteine-181 HIV
Reverse Transcriptase Enzymes. J . Med. Chem. 1995, 38, 4830-
1
mp 274-276 °C; H NMR (CDCl
.55 (s, 3 H), 4.38 (q, J ) 6 Hz, 2 H), 7.02 (dd, J ) 8, 5 Hz, 1
H), 7.30 (m, 1 H), 7.34 (d, J ) 8 Hz, 1 H), 7.50 (AB q, 2 H),
.78 (s, 1 H), 8.12 (dd, J ) 8, 2 Hz, 1 H), 8.43 (m, 2 H), 9.80
3
) δ 1.35 (t, J ) 6 Hz, 3 H),
3
7
+
(
broad s, 1 H); MS (CI) m/ z 371 (MH ); HRMS calcd for
O 371.162 034, found 371.161 76.
-(6-Aza in d ol-3-yl)-5,11-d ih yd r o-11-eth yl-5-m eth yl-6H-
d ip yr id o[3,2-b:2′,3′-e][1,4]d ia zep in -6-on e (7f): yield 14%;
21 19 6
C H N
2
8
.
(6) For a general reference on ICl, see: Sandin, R. B.; Drake, W.
V.; Leger, F. 2,6 Diiodo-p-nitroaniline. Organic Syntheses;
Wiley: New York, 1943; Coll. Vol II, pp 196-7.
1
mp 251-252 °C; H NMR (CDCl
.58 (s, 3 H), 4.35 (q, J ) 6 Hz, 2 H), 7.04 (dd, J ) 8, 5 Hz, 1
H), 7.45 (AB q, 2 H), 7.95 (s, 1 H), 8.12 (dd, J ) 8, 2 Hz, 1 H),
.30-8. 45 (m, 4 H), 8.85 (broad s, 1 H); MS (CI) m/ z 371
3
) δ 1.34 (t, J ) 6 Hz, 3 H),
3
(
7) (a) Sakamoto, T.; Satoh, C.; Kondo, Y.; Yamanaka, H. Condensed
Heteroaromatic Ring Systems. XXII Simple and General Syn-
thesis of 1H-Pyrrolopyridines. Heterocycles 1992, 34, 2379-84.
8
+
(
MH ) Anal. Calcd for C21
-(7-Aza in d ol-3-yl)-5,11-d ih yd r o-11-eth yl-5-m eth yl-6H-
d ip yr id o[3,2-b:2′,3′-e][1,4]d ia zep in -6-on e (7g): yield 7%;
H
18
N
6
O‚0.25H
2
O: C, H, N.
(b) Mahadevan, I.; Rasmussen, M. Synthesis of Pyrrolopyridines
2
(Azaindoles). J . Heterocycl. Chem. 1992, 29, 359-367.
(8) Yakhontov, L. N.; Azimov, V. A.; Lapan, E. I. About Reactivity
1
of Isomeric Azaindoles. Tetrahedron Lett. 1969, 1902-12.
9) Echavarren, A. M.; Stille, J . K. Palladium Catalyzed Coupling
mp 246-247 °C; H NMR (CDCl
.55 (s, 3 H), 4.36 (q, J ) 6 Hz, 2 H), 7.04 (dd, J ) 8, 5 Hz, 1
H), 7.26 (m, 1 H), 7.49 (AB q, 2 H), 7.86 (d, J ) 2 Hz, 1 H),
.13 (dd, J ) 8, 2 Hz, 1 H), 8.40 (m, 2 H), 8.81 (d, J ) 8 Hz, 1
3
) δ 1.35 (t, J ) 6 Hz, 3 H),
(
3
of Aryl Triflates with Organostannanes. J . Am. Chem. Soc. 1987,
1
09, 5478-86.
8
(
10) Shih, C.-K.; Rose, J . M.; Hansen, G. L.; Wu, J . C.; Bacolla, A.;
Griffin, J . A. Chimeric human immunodeficiency virus type1/
type2 reverse transcriptases display reversed sensitivity to
nonnucleoside analog inhibitors. Proc. Natl. Acad. Sci. U.S.A.
+
H), 9.42 (broad s, 1 H); MS (CI) m/ z 371 (MH ); HRMS calcd
for C21 O 371.162 034, found 371.163 44.
19 6
H N
1
991, 88, 9878-82.
Ack n ow led gm en t. The authors thank Suresh Ka-
padia for the preparation of 2 and Walter Davidson for
performing the HRMS analyses. Additionally J ohn
Proudfoot and Karl Hargrave are acknowledged for very
helpful discussions and critical reading of the manu-
script.
(
11) Romero, D. L.; Olmsted, R. A.; Poel, T. J .; Morge, R. A.; Biles,
C.; Keiser, B. J .; Kopta, L. A.; Friis, J . M.; Holsey, J . D.;
Stefanski, K. J .; Wishka, D. G.; Evans, D. B.; Morris, J .; Stehle,
R. G.; Sharma, S. K. J . Med. Chem. 1996, 39, 3769-3789.
12) Spira, T. J .; Bozeman, L. H.; Holman, R. C.; Waefield, D. T.;
Phillips, S. K.; Feorino, P. M. J . Clin. Microbiol. 1987, 25, 97-
(
(
9
.
13) (a) Mosmann, T. J . Immunol. Methods 1983, 65, 55-63. (b)
Salahuddin, S. Z.; Markham, P. D.; Wong-Staahl, F.; Franchini,
G.; Kalyanaraman, V. S.; Gallo, R. C. Virology 1983, 129, 51-64.
Su p p or tin g In for m a tion Ava ila ble: 1H-NMR spectra of
7
d , 7e, and 7g (3 pages). Ordering information is given on
any current masthead page.
J M960837Y