# Patent

## Title
Hydrophilic analogs of 4,8-dihydrobenzodithiophene-4,8-diones as anticancer agents

## Abstract

The present invention discloses hydrophilic derivatives of 4,8-dihydrobenzodithiophene-4,8-diones, which are active as anticancer agents, along with pharmaceutical formulations containing the same.

## Background
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Application No. 60/613,225, filed 28 Sep. 2004.


FIELD OF THE INVENTION
The present invention concerns hydrophilic analogs of 4,8-dihydrobenzodithiophene-4,8-diones, which are active as anticancer agents, along with pharmaceutical formulations containing the same.
BACKGROUND OF THE INVENTION
In our prior studies, naphtho[2,3-b]thiophene4,9-diones (A), 4,8-dihydrobenzo[1,2-b: 5,4-b′]dithiophene-4,8-diones(B) and, 4,8-dihydrobenzo[1,2-b: 4,5-b′]dithiophene-4,8-diones(C) were identified as potential anticancer agents [U.S. Pat. Nos. 6,174,913 B1; 6,337,346B1, details of which are incorporated herein by reference]. Among these benzothiophene analogs, many compounds possessed very potent cytotoxic activity against human tumor cell lines. However, most of these compounds were quite lipophilic, and therefore, not optimal for in vivo and clinical studies.




SUMMARY OF THE INVENTION
The present invention was undertaken to synthesize novel hydrophilic analogs of dihydrobenzodithiophenediones and to evaluate their anticancer activity.
A first aspect of the present invention is a compound selected from the group consisting of compounds of formula (D) and compounds of formula (E):




wherein Y and Z independently are O, S, —NH—, or Se, and preferably Y and Z are S;

A1 and A2 independently are O, S, or NR5, wherein R5 is H or alkyl;
R1, R2, R3 and R4 independently are H, alkyl, —CR5R6—X—C(O)—(CH2)nCOOH, —CR5R6—X—(CH2)nCOOH, —CR5R6—X—(CH2)nNR5R6, —C(O)—NR6—(CR5R6)nCOOH, —C(O)—NR6—(CR5R6)nNR5R6, —CR5R6—C(O)—(CH2)nCOOH, —CR5R6—X—C(O)—(CH2)nNR5R6, —C(O)—(CR5R6)nCOOH, —C(O)—(CR5R6)nNR5R6, —CR5═N—(CH2)nCOOH, —CR5═N—(CH2)nNR5R6, —CR5═NOH, or




wherein X is O, S, or NH; R5 is defined as above; R5 is H or alkyl; and n is 1-5; subject to the proviso that at least one of R1, R2, R3 and R4 is a radical other than hydrogen and alkyl; or a pharmaceutically acceptable salt thereof.
Preferably, R2, R3 and R4 are H, and R1 is —CR5R6—X—C(O)—(CH2)nCOOH, —CR5R6—X—(CH2)nCOOH, —CR5R6—X—(CH2)nNR5R6, —C(O)—NR6—(CR5R6)nCOOH, or —C(O)—NR6—(CR5R6)nNR5R6, wherein X, R5, R6 and n are defined as above.
Preferably, A1 and A2 are O.
Preferably, X is O.
Preferably, R5 and R6 independently are H or methyl.
Preferably, R2, R3 and R4 are H, and R1 is —CR5R6—X—C(O)—(CH2)nCOOH, wherein X, R5, R6 and n are defined as above.
Preferably, R2, R3 and R4 are H, and R1 is —CR5R6—X—(CH2)nCOOH, wherein X, R5, R6 and n are defined as above.
Preferably, R2, R3 and R4 are H, and R1 is —CR5R6—X—(CH2)nNR5R6, wherein X, R5, R6 and n are defined as above.
Preferably, R2, R3 and R4 are H, and R1 is —C(O)—NR6—(CR5R6)nCOOH, wherein X, R5, R6 and n are defined as above.
Preferably, R2, R3 and R4 are H, and R1 is —C(O)—NR6—(CR5R6)nNR5R6, wherein X, R5, R6 and n are defined as above.
Preferably, the compound of the present invention has the formula (D).
Preferably, the compound of the present invention has the formula (E).
Preferably, the compound of the present invention has the formula (D) is mono-[1-(4,8-dioxo-4,8-dihydrobenzo[1,2-b:5,4-b′]dithiophen-2-yl)-methyl]succinate (IIa-1), mono-[1-(4,8-dioxo-4,8-dihydrobenzo[1,2-b:5,4-b′]dithiophen-2-yl)ethyl]succinate (IIb-1), or mono-[1-(4,8-dioxo-4,8-dihydrobenzo[1,2-b:5,4-b′]dithiophen-2-yl)-ethyl]pentanedioate (IIb-2); and the compound of the present invention has the formula (E) is mono-[1-(4,8-dioxo-4,8-dihydroxybenzo[1,2-b;4,5-b′]dithiophen-2-yl)-ethyl]succinate (VII-1), mono-[1-(4,8-dioxo-4,8-dihydroxybenzo[1,2-b;4,5-b′]dithiophen-2-yl)-ethyl]pentanedioate (VII-2), or 4,8-dioxo-4,8-dihydrobenzo[1,2-b;4,5-b′]dithiophene-2-carboxylate-(2-dimethylamino-ethyl)-amide (XV-2).
A second aspect of the present invention is a composition comprising an effective anticancer amount of a compound of the formula (D) or (E) above, or a pharmaceutically acceptable salt thereof, in a pharmaceutically acceptable carrier.
A further aspect of the present invention is a method for treating a tumor, the method comprising administering to a subject in need of treatment a compound of the formula (D) or (E) above, or a pharmaceutically acceptable salt thereof, in an amount effective to treat said tumor.
A still further aspect of the present invention is the use of a compound of the formula (D) or (E) above, or a pharmaceutically acceptable salt thereof, for the preparation of a medicament for carrying out the method described above.
Preferably, said tumor is selected from the group consisting of non-small cell lung cancer, breast cancer, nasopharynx carcinoma, prostate cancer, colon cancer, hepatoma, ileocecal carcinoma, leukemia and central nervous system cancers, and more preferably said tumor is non-small cell lung cancer, breast cancer, nasopharynx carcinoma and prostate cancer.


DETAILED DESCRIPTION OF THE INVENTION
As part of a continuing search for potential anticancer drug candidates in the benzodithiophenedione series, novel hydrophilic analogs were synthesized and evaluated. A series of succinates (D, E) and amides (XV) derived from hydroxyalkyl-4,8-dihydrobenzo[1,2-b:5,4-b′]dithiophene-4,8-dione (I) and hydroxyalkyl-4,8-dihydrobenzo[1,2-b:4,5-b′]dithiophene-4,8-dione (VI) are worthy of further exploration for their anticancer activities.
The term “alkyl” as used herein, inidividually or as a portion of another substituent term such as “alkoxy”, refers to C1 to C4 alkyl, which may be linear or branched, and saturated or unsaturated. Preferably, the alkyl is saturated, and preferably the alkyl is linear.
The term “halogen” or “halo” as used herein refers to fluorine, chlorine, bromine, iodine, etc., or fluoro, chloro, bromo, iodo, etc., respectively.
Suitable methods for synthesizing the compounds of the present invention will be described in the following, and variations thereof will be apparent to those skilled in the art in given the Examples set forth below.
The key intermediates (I,VI) needed for the synthesis of target compounds were prepared according to our previously reported procedures [L. J. Huang, S. C. Kuo, C. Y. Perng, Y. H. Chao, T. S. Wu, A. T. Mcphail, A. Manger, H. Y. Cheng and K. H. Lee. Bioorg. Med. Chem. Lett 8, 2763-2768 (1998); Y. H. Chao, S. C. Kuo, C. H. Wu, C. Y. Lee, A. Manger, I. C. Sun, S. L. Morris-Natschke and K. H. Lee. J. Med. Chem. 41, 4658-4661 (1998); Y. H. Chao, S. C. Kuo, K. Ku, I. P. Chiu, C. H. Wu, A. Manger, H. K. Wang, and K. H. Lee. Bioorg. Med. Chem. 7, 1025-1031 (1999)].
As shown in Scheme 1. the mono-(4,8-dioxo-4,8-dihydrobenzo[1,2-b:5,4-b′]dithiophenyl-alkyl)alkanedioates (II) were obtained by treating the key intermediate I, hydroxyalkyl-4,8-dihydrobenzo[1,2-b:5,4-b′]dithiophene-4,8-diones, with anhydride in the presence of organic or inorganic base.




When the key intermediate I was reacted with a variety of haloalkanoates [X(CH2)nCOOEt] in the presence of alkali, the corresponding alkoxyalkanoates (III) were obtained. Hydrolysis of compounding III with TFA or NaOH affords the corresponding acids (IV), which could be led to water soluble salts. Reaction of key intermediates I with a variety of haloalkylamines gave the corresponding alkoxyalkylamines (V), which could be treated with HCl, respectively, to afford their water soluble salts.
On the other hand, using the key intermediates VI, hydroxyalkyl-4,8-dihydrobenzo[1,2-b:4,5-b′]dithiophene-4,8-diones, as starting materials, following the similar procedures (Scheme 2) described above for the preparation of compounds II, IV, V, we successfully converted the key intermediates VI into hydrophilic target compounds VII, IX, X.




As shown in Scheme 3, the 4,8-dihydrobenzo[1,2-b:5,4-b′]dithio-phene-4,8-dione-2-carboxylic acid XI was treated with amino acids in the presence of coupling agent to form the amides XII, which were then converted to the corresponding acids XIII. When XI was treated with NH3, the corresponding ammonium salts (XI-NH4) was obtained. On the other hand, compounds XI was allowed to react with SOCl2 to afford the corresponding acid chloride, which was treated with a variety of aminoalkylamines to give corresponding amides (XVII) which could be treated with H3PO4 respectively to afford their water soluble salts (XVII-H3PO4).




When the 4,8-dihydrobenzo[1,2-b:4,5-b′]dithiophene-4.8-dione-2-carboxylic acids (XIV) were used as starting material following the similar procedures (Scheme 4) described above for the preparation of compounds XIII-Na, XI-NH4 and XVII-H3PO4, we successfully converted the starting material XIV into target compounds XVI-Na and XIV-NH4 and XVII-H3PO4.




The following Examples are provided to further illustrate the present invention, and should not be construed as limiting thereof. All melting points were determined on a Büchi MP-540 apparatus and are uncorrected. NMR spectra were obtained on a Varian Unity Inova-500 spectrometer in DMSO-d6, CD3OD or CDCl3. The chemical shift values are expressed in δ values (parts per million). The following abbreviations are used: s=singlet, d=doublet, t=triplet, q=quartet, m=multiplet, and br=broad, Mass spectra (MS) were measured with JEOL SX102A GC-MS instrument.
EXAMPLE 1
Mono-[1-(4,8-dioxo-4,8-dihydrobenzo[1,2-b:5,4-b′]dithiophen-2-yl)-methyl]succinate IIa-1




To a stirred solution of Ia (30 mg, 0.12 mmole) in CH2Cl2 (10 ml) were added succinic anhydride (120 mg, 1.2 mmole), Et3N (25 mg, 1.23 mmole) and catalytic amount of DMAP (dimethyl aminopyridine). The reaction mixture was stirred at R.T. for 3 hr under N2 and then washed with H2O. The organic layer was extracted with aqueous NaHCO3. To the aqueous layer was added CH2Cl2 and the pH was adjusted to 1 by 6N HCl. The organic layer was washed with H2O and the volume was reduced. The solid precipitate was purified by reslurry with diethyl ether to yield yellow solid IIa-1 (13.2 mg, 30%).
1H NMR (500 MHz, CDCl3) δ 7.67 (d, J=5.0 Hz, 1H), 7.60 (dd, J=6.0, 5.0 Hz, 1H), 7.55 (d, J=6.0 Hz, 1H), 5.32 (s, 2H), 2.70 (s, 4H).
HRMS Calcd for C15H10O6S2: 349.9919, Found: 350.9995 (MH+, FAB).
mp=156° C. (decomp.)
EXAMPLE 2
Sodium mono-[1-(4,8-dioxo-4,8-dihydrobenzo[1,2-b:5,4-b′]dithiophen-2-yl)-methyl]succinate IIa-1-Na




To a stirred solution of IIa-1 (100.7 mg, 0.29 mmole) in EA was added sodium 2-ethylhexanoate (1.2 ̃1.5 eq.) in EA and stirred for overnight. The precipitate was filtered and washed with EA and then dried in vacuum. Yellow solid IIa-1-Na (100.6 mg, 93%) was obtained.
1H NMR (500 MHz, CD3OD) δ 7.96-7.93 (m, 1H), 7.63-7.60 (m, 2H), 5.36 (s, 2H), 2.63 (t, J=7.0 Hz, 2H), 2.48 (t, J=7.0 Hz, 2H).
mp=213° C. (decomp.)
EXAMPLE 3
Mono-[1-(4,8-dioxo-4,8-dihydrobenzo[1,2-b:5,4-b′]dithiophen-2-yl)-ethyl]succinate IIb-1




To a stirred solution of Ib (45 mg, 0.18 mmole) and CH2Cl2 (10 ml) were added succinic anhydride (150 mg, 1.5 mmole), Et3N (150 mg, 1.54 mmole) and catalytic amount of DMAP (dimethyl aminopyridine). The reaction mixture was stirred at R.T. for 3 hr under N2 and then washed with H2O. The organic layer was extracted with aqueous NaHCO3. To the aqueous layer was added CH2Cl2, and the pH was adjusted to 1 by 6N HCl. The separated CH2Cl2 layer was washed with H2O and the volume was reduced. The solid precipitate was purified by reslurry with diethyl ether to yield yellow solid IIb-1 (11.7 mg, 17%).
1H NMR (500 MHz, CDCl3) δ 7.66 (d, J=5.0 Hz, 1H), 7.59 (d, J=5.0 Hz, 1H), 7.50 (s, 1H), 6.15 (q, J=6.0 Hz, 1H), 2.71-2.65 (m, 4H), 1.67 (d, J=6.0 Hz, 3H).
HRMS Calcd for C16H12O6S2: 364.0075, Found: 364.0074.
mp=132 ̃132.5° C.
EXAMPLE 4
Sodium mono-[1-(4,8-dioxo-4,8-dihydroxybenzo-[1,2-b;5,4-b′]dithiophen-2-yl)-ethyl]succinate IIb-1-Na




To a stirred solution of IIb-1 (100.8 mg, 0.28 mmole) in EA was added sodium 2-ethylhexanoate (1.2 ̃1.5 eq.) in EA and stirred for overnight. The precipitate was filtered and washed with EA and then dried in vacuum. Yellow solid IIb-1-Na (96.5 mg, 89%) was obtained.
1H NMR (500 MHz, CD3OD) δ 7.94 (d, J=5.0 Hz, 1H), 7.61 (d, J=5.0 Hz, 1H), 7.57 (s, 1H), 6.17 (q, J=6.5 Hz, 1H), 2.68-2.56 (m, 2H), 2.50-2.45 (m, 2H), 1.68 (d, J=6.5 Hz, 3H).
mp=219° C. (decomp.)
EXAMPLE 5
Mono-[1-(4,8-dioxo-4,8-dihydroxybenzo[1,2-b;4,5-b′]dithiophen-2-yl)-ethyl]succinate VII-1




To a stirred solution of VI (50.0 mg, 0.19 mmole) and CH2Cl2 (3 ml) were added succinic anhydride (44.8 mg, 0.45 mmole), Et3N (0.10 ml, 0.43 mmole) and DMAP (3.0 mg, 0.02 mmole). The reaction mixture was stirred at R.T. for 1.5 hr under N2. After the addition of H2O (1 ml) and 6N HCl (1 ml), the reaction mixture was extracted with CH2Cl2 (15 ml×3). The organic layer was dried over Na2SO4, filtered and concentrated to yield yellow-green solid VII-1 (62.0 mg, 90%).
1H NMR (500 MHz, d6-DMSO) δ 8.15 (d, J=4.5 Hz, 1H), 7.63 (s, 2H), 6.14 (q, J=6.5 Hz, 1H), 2.59-2.56 (m, 4H), 1.61 (d, J=6.5 Hz, 3H).
HRMS Calcd for C16H12O6S2: 364.0075, Found: 365.0156 (MH+, FAB).
Mp=163.5 ̃164.6° C.
EXAMPLE 6
Sodium mono-[1-(4,8-dioxo-4,8-dihydroxybenzo-[1,2-b;4,5-b′]dithiophen-2-yl)-ethyl]succinate VII-1-Na




To a stirred solution of VII-1 (200.0 mg, 0.55 mmole) in EA was added sodium 2-ethylhexanoate (1.2 ̃1.5 eq.) in EA and stirred for overnight. The precipitate was filtered and washed with EA and then dried in vacuum. Yellow-green solid VII-1-Na (191.0 mg, 90%) was obtained.
1H NMR (500 MHz, CD3OD) δ 7.93 (d, J=5.0 Hz, 1H), 7.62 (d, J=5.0 Hz, 1H), 7.57 (s, 1H), 6.17 (q, J=6.5 Hz, 1H), 2.68-2.56 (m, 2H), 2.49-2.45 (m, 2H), 1.67 (d, J=6.5 Hz, 3H).
mp=240° C. (decomp.)
EXAMPLE 7
Mono-[1-(4,8-dioxo-4,8-dihydrobenzo[1,2-b:5,4-b′]dithiophen-2-yl)-methyl]pentanedioate IIa-2




To a stirred solution of Ia (54.0 mg, 0.22 mmole) and CH2Cl2 (3 ml) were added glutaric anhydride (49.7 mg, 0.44 mmole), DMAP (3.0 mg, 0.02 mmole) and Et3N (0.06 ml, 0.40 mmole). The reaction mixture was stirred at R.T. for 3.5 hr under N2. After the addition of H2O (1 ml) and 2N HCl (3 ml), the reaction mixture was extracted with CH2Cl2 (15 ml×3). The organic layer was dried over Na2SO4, filtered and concentrated to get crude product. It was purified by column chromatography on silica gel eluting with CH3OH: CH2Cl2 (1:40) to obtain compound IIa-2 (45.9 mg, 58%).
1H NMR (500 MHz, CDCl3) δ 7.67 (d, J=5.0 Hz, 1H), 7.61 (dd, J=5.5, 5.0 Hz, 1H), 7.55 (d, J=5.5 Hz, 1H), 5.29 (s, 2H), 2.48 (t, J=7.5 Hz, 2H), 2.44 (t, J=7.5 Hz, 2H), 2.02-1.95 (m, 2H).
HRMS Calcd for C16H12O6S2: 364.0075, Found: 364.0086.
mp=220° C. (decomp.)
EXAMPLE 8
Sodium mono-[1-(4,8-dioxo-4,8-dihydrobenzo[1,2-b:5,4-b′]dithiophen-2-yl)methyl]pentanedioate IIa-2-Na




To a stirred solution of IIa-2 (67.1 mg, 0.18 mmole) in EA was added sodium 2-ethylhexanoate (1.2 ̃1.5 eq.) in EA and stirred for overnight. The precipitate was filtered and washed with EA and then dried in vacuum. Yellowish brown solid IIa-2-Na (65.0 mg, 94%) was obtained.
1H NMR (500 MHz, CD3OD) δ 7.97-7.92 (m, 1H), 7.65-7.58 (m, 2H), 5.36 (s, 2H), 2.45 (t, J=7.8 Hz, 2H), 2.21 (t, J=7.8 Hz, 2H), 1.94-1.88 (m, 2H).
mp=203° C. (decomp.)
EXAMPLE 9
Mono-[1-(4,8-dioxo-4,8-dihydrobenzo[1,2-b:5,4-b′]dithiophen-2-yl)-ethyl]pentanedioate IIb-2




To a stirred solution of Ib (100.0 mg, 0.4 mmole) in CH2Cl2 (3 ml) were added glutaric anhydride (136.9 mg, 1.2 mmole), DMAP (5.0 mg, 0.04 mmole) and Et3N (121 mg, 1.19 mmole). The reaction mixture was stirred at R.T. for overnight under N2. After the addition of H2O (1 ml) and 2N HCl (3 ml), the reaction mixture was extracted with CH2Cl2 (15 ml×3). The CH2Cl2 layer was dried over Na2SO4, filtered and concentrated to get crude product. It was purified by column chromatography on silica gel eluting with CH3OH: CH2Cl2 (1:40) to obtain compound IIb-2 (128.0 mg, 88%).
1H NMR (500 MHz, CDCl3) δ 7.65 (d, J=5.0 Hz, 1H), 7.59 (d, J=5.0 Hz, 1H), 7.49 (s, 1H), 6.13 (q, J=6.5 Hz, 1H), 2.47-2.40 (m, 4H), 2.00-1.93 (m, 2H, 1.66 (d, J=6.5 Hz, 3H).
HRMS Calcd for C17H14O6S2: 378.0232, Found: 378.0229.
mp=100.5 ̃101.0° C.
EXAMPLE 10
Sodium mono-[1-(4,8-dioxo-4,8-dihydroxybenzo[1,2-b;5,4-b′]dithiophen-2-yl)-ethyl]pentanedioate IIb-2-Na




To a stirred solution of IIb-2 (83.0 mg, 0.22 mmole) in EA was added sodium 2-ethylhexanoate (1.2 ̃1.5 eq.) in EA and stirred for overnight. The precipitate was filtered and washed with EA and then dried in vacuum. Yellowish brown solid IIb-2-Na (83.1 mg, 94%) was obtained.
1H NMR (500 MHz, CD3OD) δ 7.94 (d, J=5.0 Hz, 1H), 7.62 (d, J=5.0 Hz, 1H), 7.57 (d, J=1.0 Hz, 1H), 6.18 (dd, J=6.5, 1.0 Hz, 1H), 2.43 (td, J=7.5, 2.5 Hz, 2H), 2.21 (t, J=7.5 Hz, 2H), 1.94-1.88 (m, 2H), 1.67 (d, J=6.5 Hz, 3H).
mp=228° C. (decomp.)
EXAMPLE 11
Mono-[1-(4,8-dioxo-4,8-dihydroxybenzo[1,2-b;4,5-b′]dithiophen-2-yl)-ethyl]pentanedioate VII-2




To a stirred solution of VI (50.0 mg, 0.19 mmole) in CH2Cl2 (3 ml) were added glutaric anhydride (45.2 mg, 0.4 mmole), DMAP (3.0 mg, 0.02 mmole) and Et3N (0.05 ml, 0.4 mmole). The reaction mixture was stirred at R.T. for 15 hr under N2. After the addition of H2O-(1 ml) and 2N HCl (3 ml), the reaction mixture was extracted with CH2Cl2 (15 ml×3). The CH2Cl2 layer was dried over Na2SO4, filtered and concentrated to get crude product. It was purified by column chromatography on silica gel eluting with CH3O: CH2Cl2 (1:50) to obtain compound VII-2 (32.7 mg, 46%).
1H NMR (500 MHz, CDCl3) δ 7.65 (d, J=5.0 Hz, 1H), 7.61 (d, J=5.0 Hz, 1H), 7.51 (s, 1H), 6.13 (q, J=6.5 Hz, 1H), 2.47-2.41 (m, 4H), 2.00-1.94 (m, 2H 1.66 (d, J=6.5 Hz, 3H).
HRMS Calcd for C17H14O6S2: 378.0232, Found: 379.0313 (MH+, FAB).
mp=141.6 ̃142.4° C.
EXAMPLE 12
Sodium mono-[1-(4,8-dioxo-4,8-dihydroxybenzo[1,2-b;4,5-b′]dithiophen-2-yl)-ethyl]pentanedioate VII-2-Na




To a stirred solution of VII-2 (109.4 mg, 0.29 mmole) in EA was added sodium 2-ethylhexanoate (1.2 ̃1.5 eq.) in EA and stirred for overnight. The precipitate was filtered and washed with EA and then dried in vacuum. Yellow-green solid VII-2-Na (79.0 mg, 68%) was obtained.
1H NMR (500 MHz, CD3OD) δ 7.93 (d, J=5.0 Hz, 1H), 7.62 (d, J=5.0 Hz, 1H), 7.57 (s, 1H), 6.17 (q, J=6.5 Hz, 1H), 2.44 (td, J=7.5, 2.5 Hz, 2H), 2.22 (t, J=7.5 Hz, 2H), 1.95-1.88 (m, 2H), 1.68 (d, J=6.5 Hz, 3H).
mp=230° C. (decomp.)
EXAMPLE 13
t-Butyl 4,8-dioxo-4,8-dihydroxybenzo[1,2-b:5,4-b′]-dithiophen-2-yl-methoxy acetate IIIa-1




To a stirred solution of compound Ia (9.4 mg, 0.04 mmole) in toluene (2 ml) were added tetrabutylammonium hydrogen sulfate (4.0 mg, 0.01 mmole), 50% NaOH(aq.) (1 ml) and t-butyl bromoacetate (0.02 ml, 0.1 mmole). The mixture was stirred at R.T. for 2 hr. After the addition of H2O, the reaction mixture was extracted with CH2Cl2 (15 ml×3). The CH2Cl2 layer was dried over Na2SO4, filtered and concentrated to get crude product. It was purified by plate liquid chromatography eluting with Ethyl acetate: Hexane (1:8) to obtain yellow solid IIIa-1 (2.7 mg, 20%).
1H NMR (500 MHz, CDCl3) δ 7.65 (d, J=5.0 Hz, 1H), 7.60 (dd, J=5.5, 5.0 Hz, 1H), 7.49 (d, J=5.5 Hz, 1H), 4.83 (s, 2H), 4.05 (s, 2H), 1.48 (s, 9H).
HRMS Calcd for C17H16O5S2: 364.0439, Found: 364.0425
mp=97.2 ̃97.8° C.
EXAMPLE 14
Ethyl 4,8-dioxo-4,8-dihydroxybenzo[1,2-b:5,4-b′]-dithiophen-2-yl-methoxy acetate IIIa




To a stirred solution of compound Ia (40 mg, 0.17 mmole) and toluene (10 ml) were added tetrabutylammonium hydrogen sulfate (20 mg, 0.06 mmole), 50% NaOH(aq.) (1 ml) and ethyl bromoacetate (0.1 ml, 0.9 mmole). The mixture was stirred at R.T. for 2 hr. After the addition of H2O, the reaction mixture was extracted with CH2Cl2 (25 ml×3). The CH2Cl2 layer was dried over Na2SO4, filtered and concentrated to get crude product. It was purified by plate liquid chromatography eluting with CH2Cl2 to obtain yellow solid IIIa (18 mg, 33%).
1H NMR (500 MHz, CDCl3) δ 7.65 (d, J=5.0 Hz, 1H), 7.62-7.59 (m, 1H), 7.51-7.49 (m, 1H), 4.85 (s, 2H), 4.24 (q, J=7.0 Hz, 2H), 4.16 (s, 2H), 1.29 (t, J=7.0 Hz, 3H).
HRMS Calcd for C15H12O5S2: 336.0126, Found: 336.0125.
mp=113.3 ̃113.5° C.
EXAMPLE 15
4,8-dioxo-4,8-dihydroxybenzo[1,2-b:5,4-b′]-dithiophen-2-yl-methoxy acetic acid IVa




To a stirred solution of compound IIIa-1 (2.7 mg, 0.007 mmole) and CH2Cl2 (1 ml) was added trifluoroacetic acid (0.1 ml) and stirred at R.T. for 1.5 hr under N2. After concentration, yellow solid IVa was obtained.





In a 25 mL flask were placed compound IIIa (15 mg, 0.05 mmole) and MeOH (10 ml). LiOH (10 mg) in H2O (8 ml) was then added and reaction mixture stirred at R.T. until hydrolysis completed. HOAc ( ̃0.4 ml) was added drop-wise to neutralize. MeOH was removed under vacuum and the residue was treated with aq. Na2CO3 and then extracted with CH2Cl2. The aqueous layer was acidified with dilute HCl solution until pH ̃4 and the extracted with CH2Cl2. The CH2Cl2 layer was dried with Na2SO4, filtered and concentrated to obtain yellow solid IVa (12.5 mg, 91%).
1H NMR (500 MHz, d6-DMSO) δ 8.15 (d, J=5.0 Hz, 1H), 7.62 (dd, J=5.0, 4.5 Hz, 1H), 7.57 (d, J=4.5 Hz, 1H), 6.47 (s, 1H), 4.85 (s, 2H), 4.16 (s, 2H).
HRMS Calcd for C13H8O5S2: 307.9813, Found: 307.9847.
mp=218.0 ̃218.2° C.
EXAMPLE 16
Sodium 4,8-dioxo-4,8-dihydroxybenzo[1,2-b:5,4-b′]-dithiophen-2-yl-methoxy acetate IVa-Na




To a stirred solution of IVa (47.8 mg, 0.16 mmole) in EA was added sodium 2-ethylhexanoate (1.2 ̃1.5 eq.) in EA and stirred for overnight. The precipitate was filtered and washed with EA and then dried in vacuum. Yellow-green solid IVa -Na (35.4 mg, 70%).was obtained.
1H NMR (500 MHz, CD3OD) δ 7.93 (br, 1H), 7.62 (br, 1H), 7.54 (s, 1H), 4.88 (s, 2H), 3.97 (s, 2H).
mp=232.7° C. (decomp.)
EXAMPLE 17
t-Butyl 1-(4,8-dioxo-4,8-dihydroxybenzo[1,2-b:5,4-b′]-dithiophen-2-yl-ethoxy)-acetate IIIb-1




To a stirred solution of compound Ib (9.4 mg, 0.04 mmole) in toluene (2 ml) were added tetrabutylammonium hydrogen sulfate (4.0 mg, 0.01 mmole), 50% NaOH(aq.) (1 ml) and t-butyl bromoacetate (0.02 ml, 0.1 mmole). The mixture was stirred at R.T. for 2 hr. After the addition of H2O, the reaction mixture was extracted with CH2Cl2 (15 ml×3), and the organic layer was dried over Na2SO4, filtered and concentrated to get crude product. It was purified by plate liquid chromatography eluting with ethyl acetate: Hexane (1:15) to obtain yellow solid IIIb-1 (6.9 mg, 51%).
1H NMR (500 MHz, CDCl3) δ 7.60 (d, J=5.0 Hz, 1H), 7.595 (d, J=5.0 Hz, 1H), 7.45 (s, 1H), 4.88 (q, J=6.5 Hz, 1H), 4.02, 3.91 (ABq, J=16.5 Hz, 2H), 1.62 (d, J=6.5 Hz, 3H), 1.46 (s, 9H).
HRMS Calcd for C18H18O5S2: 378.0596, Found, 378.0587
mp=108.0 ̃108.7° C.
EXAMPLE 18
Ethyl 1-(4,8-dioxo-4,8-dihydroxybenzo[1,2-b:5,4-b′]-dithiophen-2-yl-ethoxy)-acetate IIIb




To a stirred solution of compound Ib (100 mg, 0.4 mmole) in toluene (20 ml) were added tetrabutylammonium hydrogen sulfate (40 mg, 0.11 mmole), 50% NaOH(aq.) (1 ml) and ethyl bromoacetate (0.2 ml, 1.8 mmole). The mixture was stirred at R.T. for 2 hr. After the addition of H2O, the reaction mixture was extracted with CH2Cl2 (20 ml×3). The CH2Cl2 layer was dried over Na2SO4, filtered and concentrated to get crude product. It was purified by plate liquid chromatography eluting with CH2Cl2 to obtain yellow solid. IIIb (65 mg, 48%).
1H NMR (500 MHz, CDCl3) δ 7.65 (d, J=5.0 Hz, 1H), 7.60 (d, J=5.0 Hz, 1H), 7.46 (s, 1H), 4.89 (q, J=6.5 Hz, 1H), 4.21 (q, J=7.0 Hz, 2H), 4.12, 4.02 (ABq, J=16.5 Hz, 2H), 1.63 (d, J=6.5 Hz, 3H), 1.27 (t, J=7.0 Hz, 3H).
HRMS Calcd for C16H14O5S2: 350.0283, Found: 350.0271.
mp=122.7 ̃122.9° C.
EXAMPLE 19
1-(4,8-Dioxo-4,8-dihydroxybenzo[1,2-b;5,4-b′]-dithiophen-2-yl-ethoxy)-acetic acid IVb




In a 100 mL flask were placed compound IIIb (65 mg, 0.19 mmole) and MeOH (15 ml). LiOH (25.0 mg) in H2O (12 ml) was then added and reaction mixture stirred at R.T. until hydrolysis completed. HOAc ( ̃1.4 ml) was added drop-wise to neutralize. MeOH was removed under vacuum and the residue was treated with aq. Na2CO3 and then extracted with CH2Cl2. The aqueous layer was acidified with dilute HCl solution until pH ̃4 and the extracted with CH2Cl2. The CH2Cl2 layer was dried with Na2SO4, filtered and concentrated to obtain yellow solid IVb (54 mg, 90%).
1H NMR (500 MHz, CD3 OD) δ 7.95 (d, J=5.0 Hz, 1H), 7.62 (d, J=5.0 Hz, 1H), 7.53 (s, 1H), 4.98 (q, J=6.5 Hz, 1H), 4.15, 4.09 (ABq, J=16.5 Hz, 2H), 1.61 (d, J=6.5 Hz, 3H).
HRMS Calcd for C14H10O5S2: 321.9970, Found: 321.9994.
mp=172.6 ̃173.0° C.
EXAMPLE 20
Sodium 1-(4,8-dioxo-4,8-dihydroxybenzo[1,2-b:5,4b′]-dithiophen-2-yl-ethoxy)-acetate IVb-Na




To a stirred solution of IVb (53.0 mg, 0.16 mmole) in EA was added sodium 2-ethylhexanoate (1.2 ̃1.5 eq.) in EA and stirred for overnight. The precipitate was filtered and washed with EA and then dried in vacuum. Yellow-green solid IVb-Na (33.1 mg, 58%) was obtained.
1H NMR (500 MHz, D2O) δ 7.87 (d, J=5.0 Hz, 1H), 7.32 (d, J=5.0 Hz, 1H), 7.27 (s, 1H), 4.98 (q, J=6.5 Hz, 1H), 4.02, 3.94 (ABq, J=16.0 Hz, 2H), 1.64 (d, J=6.5 Hz, 3H).
mp=243.8 ̃244.2° C.
EXAMPLE 21
t-Butyl 1-(4,8-dioxo-4,8-dihydroxybenzo[1,2-b:4,5-b′]-dithiophen-2-yl-ethoxy)acetate VIII-1




To a stirred solution of compound VI (9.0 mg, 0.03 mmole) in toluene (2 ml) were added tetrabutylammonium hydrogen sulfate (4.0 mg, 0.01 mmole), 50% NaOH(aq.) (1 ml) and t-butyl bromoacetate (0.02 ml, 0.1 mmole). The mixture was stirred at R.T. for 2 hr. After the addition of H2O, the reaction mixture was extracted with CH2Cl2 (15 ml×3), and the organic layer was dried over Na2SO4, filtered and concentrated to get crude product. It was purified by plate liquid chromatography eluting with ethyl acetate: Hexane (1:15) to obtain yellow oil VIII-1 (5.0 mg, 39%).
1H NMR (500 MHz, CDCl3) δ 7.65 (d, J=5.0 Hz, 1H), 7.61 (d, J=5.0 Hz, 1H), 7.46 (s, 1H), 4.87 (q, J=6.5 Hz, 1H), 4.01, 3.90 (ABq, J=16.5 Hz, 2H), 1.62 (d, J=6.5 Hz, 3H), 1.46 (s, 9H).
HRMS Calcd for C18H18O5S2: 378.0596, Found: 378.0573
EXAMPLE 22
Ethyl 1-(4,8-dioxo-4,8-dihydroxybenzo[1,2-b:4,5-b′]-dithiophen-2-yl-ethoxy)acetate VIII




To a stirred solution of compound VI (9.7 mg, 0.04 mmole) and toluene (2 ml) were added tetrabutylammonium hydrogen sulfate (4.0 mg, 0.01 mmole), 50% NaOH(aq.) (1 ml) and ethyl bromoacetate (0.1 mmole). The mixture was stirred at R.T. for 2 hr. After the addition of H2O, the reaction mixture was extracted with CH2Cl2 (15 ml×3). The CH2Cl2 layer was dried over Na2SO4, filtered and concentrated to get crude product. It was purified by plate liquid chromatography eluting with CH2Cl2 to obtain yellow solid VIII (2.5 mg, 19%).
1H NMR (500 MHz, CDCl3) δ 7.65 (d, J=5.0 Hz, 1H), 7.61 (d, J=5.0 Hz, 1H), 7.47 (s, 1H), 4.89 (q, J=6.5 Hz, 1H), 4.21 (q, J=7.0 Hz, 2H), 4.12, 4.02 (ABq, J=16.5 Hz, 2H), 1.63 (d, J=6.5 Hz, 3H), 1.27 (t, J=7.0 Hz, 3H).
HRMS Calcd for C16H14O5S2: 350.0283, Found: 350.0284.
mp=106.2 ̃107.1° C.
EXAMPLE 23
1-(4,8-Dioxo-4,8-dihydroxybenzo[1,2-b:4,5-b′]-dithiophen-2-yl-ethoxy)-acetic acid IX




In a 25 mL flask were placed compound VIII (192.7 mg, 0.55 mmole) and MeOH (30 ml). LiOH (0.36 g) in H2O (30 ml) was then added and reaction mixture stirred at R.T. until hydrolysis completed. HOAc ( ̃1.1 ml) was added drop-wise to neutralize. MeOH was removed under vacuum and the residue was treated with aq. Na2CO3 and then extracted with EA. The aqueous layer was acidified with dilute HCl solution until pH ̃4 and the extracted with EA. The EA layer was dried with Na2SO4, filtered and concentrated to obtain yellow solid IX (160.0 mg, 90%).
1H NMR (500 MHz, CD3OD) δ 7.90 (d, J=5.0 Hz, 1H), 7.60 (d, J=5.0 Hz, 1H), 7.51 (s, 1H), 4.96 (q, J=6.5 Hz, 1H), 4.15, 4.09 (ABq, J=16.5 Hz, 2H), 1.61 (d, J=6.5 Hz, 3H).
HRMS Calcd for C14H10O5S2: 321.9970, Found: 323.0054 (MH+, FAB).
mp=172.1 ̃172.8° C.
EXAMPLE 24
Sodium 1-(4,8-dioxo-4,8-dihydroxybenzo[1,2-b:4,5-b′]-dithiophen-2-yl-ethoxy)-acetate IX-Na




To a stirred solution of IX (85.0 mg, 0.28 mmole) in EA was added sodium 2-ethylhexanoate (1.2 ̃1.5 eq.) in EA and stirred for overnight, The precipitate was filtered and washed with EA and then dried in vacuum. Yellow solid IX-Na (83.0 mg, 92%) was obtained.
1H NMR (500 MHz, CD3OD) δ 7.92 (d, J=5.0 Hz, 1H), 7.62 (d, J=5.0 Hz, 1H), 7.52 (s, 1H), 4.96 (q, J=6.5 Hz, 1H), 3.92, 3.83 (ABq, J=15.5 Hz, 2H), 1.60 (d, J=6.5 Hz, 3H).
mp=223° C. (decomp.)
EXAMPLE 25
2-[1-(2-Pyrrol-1-yl-propoxy)-ethylbenzo[1,2-b:4,5-b′]dithiophen-4,8-dione X




To a stirred solution of compound VI (10.5 mg, 0.04 mmole) in toluene (2 ml) were added tetrabutylammonium hydrogen sulfate (4.0 mg, 0.01 mmole), 50% NaOH(aq.) (2 ml) and 1-(3-bromopropyl)pyrrole (0.1 mmole). The mixture was stirred at R.T. for 3 hr. After the addition of H2O, the reaction mixture was extracted with CH2Cl2 (15 ml×3). The CH2Cl2 layer was dried over Na2SO4, filtered and concentrated to get crude product. It was purified by plate liquid chromatography eluting with CH2Cl2 to obtain yellow oil X (5.0 mg, 34%).
1H NMR (500 MHz, CDCl3) δ 7.65 (d, J=5.0 Hz, 1H), 7.61 (d, J=5.0 Hz, 1H), 7.41 (s, 1H), 6.61 (s, 2H), 6.10 (s, 2H), 4.64 (q, J=6.5 Hz; 1H), 4.06-3.94 (m, 2H), 3.38 (t, J=5.5 Hz, 2H), 2.04-1.99 (m, 2H), 1.56 (d, J=6.5 Hz, 3H).
HRMS Calcd for C19H17NO3S2: 371.0650, Found: 371.0663
EXAMPLE 26
4,8-dioxo-4,8-dihydrobenzo[1,2-b;5,4-b′]dithiophene-2-carboxylate-(2-dimethylamino-ethyl)-amide XVII




Compound XI (60 mg, 0.23 mmole) in SOCl2 (5 ml) was heated to reflux for 2 hrs. The excess SOCl2 was removed to yield crude acid chloride. The acid chloride obtained was used directly without purification. It was diluted with CH2Cl2 (4 ml) and added to the N,N-dimethylethylenediamine (1.5 ml), Et3N (2 ml) and CH2Cl2 (4 ml) mixture and stirred at R.T. for 1.5 ̃2 hrs. Water was added and the reaction mixture extracted with CH2Cl2, The CH2Cl2 layer was concentrated and crude product was purified through column using MeOH: CH2Cl2=1:8 as the eluent. Yellow solid XVII (50.0 mg, 67%) was obtained.
1H NMR (500 MHz, CD3OD) δ 8.14 (d, J=2.0 Hz, 1H), 7.97 ̃8.00 (m, 1H), 7.65 (d, J=5.0 Hz, 1H), 3.54 (t, J=6.5 Hz, 2H), 2.59 (t, J=6.5 Hz, 2H), 2.33 (s, 6H).
HRMS Calcd for C15H14N2O3S2: 334.0446, Found: 334.0435
mp=197.5 ̃198.0° C.
EXAMPLE 27
4,8dioxo-4,8-dihydrobenzo[1,2-b;5,4-b′]dithiophene-2-carboxylate-(2-dimethyl-aminoethyl)-amide phosphoric acid salt XVII-H3PO4




To a stirred solution of XVII (31 mg, 0,093 mmole) in THF was added 85% H3PO4 (1.2 ̃1.5 eq.) and stirred for overnight. The precipitate was filtered and washed with THF and then dried in vacuum. Yellow solid XVII-H3PO4 (39 mg, 97%) was obtained.
1H NMR (500 MHz, D2O) δ 8.16 (s, 1H), 8.02 (d, J=5.0 Hz, 1H), 7.66 (d, J=5.0 Hz, 1H), 3.78 (t, J=6.0 Hz, 2H), 3.37 (t, J=6.0 Hz, 2H), 2.97 (s, 6H).
mp=222.5° C. (decomp.)
EXAMPLE 28
(a) Ammonium 4,8-dioxo-4,8-dihydrobenzo-[1,2-b:5,4-b′]dithiophene-2-carboxylate XI-NH4




Aqueous ammonium hydroxide (29.5%) was added to the solution of compound XI (230 mg, 0.87 mmole) in IPA (40 mL) until basic. After stirring for a while, all the volatile solvent was removed to yield green-yellow solid XI-NH4 (200 mg, 82%)
1H NMR (500 MHz, CD3OD) δ 7.94 (d, J=5.0 Hz, 1H), 7.91 (s, 1H), 7.62 (d, J=5.0 Hz, 1H).
mp=257 ̃259° C.
(b) Sodium 4,8-dioxo-4,8-dihydrobenzo-[1,2-b:5,4-b′]dithiophene-2 carboxylate XI-Na




To a stirred solution of XI (206.7 mg, 0.83 mmole) in EA was added sodium 2-ethylhexanoate (1.2 ̃1.5 eq.) in EA and stirred for overnight. The precipitate was filtered and washed with EA and then dried in vacuum. Yellowish brown solid XI-Na (202.5 mg, 90%) was obtained.
1H NMR (500 MHz, CD3OD) δ 7.93 (dd, J=5.0, 2.0 Hz, 1H), 7.90 (d, J=2.0 Hz, 1H), 7.62 (d, J=5.0 Hz, 1H).
mp=>275° C. (decomp.)
EXAMPLE 29
(2S)-[(4,8-Dioxo-4,8-dihydroxybenzo[1,2-b:5,4-b′]dithiophen-2-carbonyl)-amino]-phenyl-acetic acid methyl ester XII-1




To a stirred solution of XI (40.0 mg, 0.15 mmole) and THF (2 ml) were added (S)-phenyl glycine methyl ester HCl salt (31 mg, 0.15 mmole), EDC (30.5 mg, 0.16 mmole), HOBt (21 mg, 0.15 mmole) and 4-ethylmorpholine (0.02 ml, 0.15 mmole). After stirring at R.T. for overnight under N2, the solvent was removed under reduced pressure. CH2Cl2 (3 ml) was added to the residue and the insoluble solid was removed. The CH2Cl2 layer was then washed with saturated NaHCO3 solution, 1M KHSO4, saturated NaHCO3 solution and H2O. The organic layer was dried over Na2SO4, filtered and concentrated to get crude product. It was purified by column chromatography on silica gel eluting with EA: Hexanes (1:3) to obtain yellow solid XII-1 (21.1 mg, 34%).
1H NMR (500 MHz, CDCl3) δ 7.95 (s, 1H), 7.71 (d, J=4.3 Hz, 1H), 7.64 (d, J=4.3 Hz, 1H), 7.41-7.30 (m, 5H), 7.16 (d, J=6.5 Hz, 1H), 5.71 (d, J=6.5 Hz, 1H), 3.78 (s, 3H).
HRMS Calcd for C20H13NO5S2: 411,0235, Found: 411.0229
mp=211.1 ̃211.9° C.
EXAMPLE 30
[(4,8-Dioxo-4,8-dihydroxybenzo[1,2-b;5,4-b′]dithiophen-2-carbonyl)-amino]-acetic acid isopropyl ester XII-2




To a stirred solution of XI (52.6 mg, 0.20 mmole) and THF (2 ml) were added isopropyl glycinate HCl salt (30.4 mg, 0.21 mmole), EDC (40.1 mg, 0.21 mmole), HOBt (27.0 mg, 0.21 mmole) and 4-ethylmorpholine (0.03 ml, 0.21 mmole). After stirring at R.T. for overnight under N2, the solvent was removed under reduced pressure. CH2Cl2 (3 ml) was added to the residue and the insoluble solid was removed. The CH2Cl2 layer was then washed with saturated NaHCO3 solution, 1M KHSO4, saturated NaHCO3 solution and H2O. The organic layer was dried over Na2SO4, filtered and concentrated to get crude product. It was purified by column chromatography on silica gel eluting with EA: CH2Cl2 (1:20) to obtain yellow solid XII-2 (31.7 mg, 44%).
1H NMR (500 MHz, CDCl3) δ 7.94 (s, 1H), 7.71 (d, J=4.5 Hz, 1H), 7.63 (d, J=4.5 Hz, 1H), 6.73 (s, 1H), 5.12 (septet, J=6.5 Hz, 1H), 4.18 (d, J=4.5 Hz, 2H), 1.29 (d, J=6.5 Hz, 6H).
HRMS Calcd for C16H13NO5S2: 363.0235, Found: 363.0226
mp=240.2 ̃240.5° C.
EXAMPLE 31
(2S)-[(4,8-Dioxo-4,8-dihydroxybenzo[1,2-b;4,5b′]dithiophen-2-carbonyl)-amino]-propionic acid methyl ester XII




To a stirred solution of XI (40.0 mg, 0.15 mmole) and THF (2 ml) were added (S)-alanine methyl ester HCl salt (21 mg, 0.15 mmole), EDC (30.5 mg, 0.16 mmole), HOBt (21 mg, 0.15 mmole) and 4-ethylmorpholine (0.02 ml, 0.15 mmole). After stirring at R.T. for overnight under N2, the solvent was removed under reduced pressure. CH2Cl2 (3 ml) was added to the residue and the insoluble solid was removed. The CH2Cl2 layer was then washed with saturated NaHCO3 solution, 1M KHSO4, saturated NaHCO3 solution and H2O. The organic layer was dried over Na2SO4, filtered and concentrated to get crude product. It was purified by column chromatography on silica gel eluting with EA: Hexanes (1:2) to obtain yellow solid XII (27.5 mg, 52%).
1H NMR (500 MHz, CDCl3) δ 7.92 (s, 1H), 7.72 (d, J=5.0 Hz, 1H), 7.64 (d, J=5.0 Hz, 1H), 6.75 (d, J=6.5 Hz, 1H), 4.78-4.72 (m, 1H), 3.80 (s, 3H), 1.54 (d, J=7.0 Hz, 3H).
HRMS Calcd for C15H11NO5S2: 349.0079, Found: 349.0061.
mp=188.1 ̃188.6° C.
EXAMPLE 32
(L)-2-{(4,8-Dioxo-4,8-dihydrobenzo-[1,2-b;5,4-b′]dithiophene-2-carbonyl)-amino}-propionic acid XIII




In a 25 mL flask were placed compound XII (130 mg, 0.37 mmole) and MeOH (37 ml), LiOH (322.5 mg) in H2O (30 ml) was then added and reaction mixture stirred at R.T. until hydrolysis completed. HOAc ( ̃1.0 ml) was added dropwise to neutralize. MeOH was removed under vacuum and the residue was treated with aq. Na2CO3 and then extracted with EA. The aqueous layer was acidified with dilute HCl solution until pH ̃4 and the extracted with EA. The EA layer was dried with Na2SO4, filtered and concentrated to obtain yellow solid XIII (120 mg, 96%).
1H NMR (500 MHz, CD3OD) δ 8.25 (s, 1H), 8.00 (d, J=5.0 Hz, 1H), 7.66 (d, J=5.0 Hz, 1H), 4.58 (q, J=7.5 Hz, 1H), 1.53 (d, J=7.5 Hz, 3H).
HRMS Calcd for C14H9NO5S2: 334.9922, Found; 334.9931
mp=239° C. (decomp.)
EXAMPLE 33
Sodium (L)-2-{(4,8-dioxo-4,8-dihydrobenzo-[1,2-b;5,4-b′]dithiophene-2-carbonyl)-amino}-propionate XIII-Na




To a stirred solution of XIII (50.5 mg, 0.15 mmole) in EA was added sodium 2-ethylhexanoate (1.2 ̃1.5 eq.) in EA and stirred for overnight. The precipitate was filtered and washed with EA and then dried in vacuum. Yellow solid XIII-Na (27.8 mg, 52%) was obtained.
1H NMR (50 MHz, D2O) δ 7.93 (br, 1H), 7.80 (d, J=5.0 Hz, 1H), 7.44 (d, J=5.0 Hz, 1H), 4.31 (q, J=6.5 Hz, 1H), 1.50 (d, J=6.5 Hz, 3H).
mp=200.5° C. (decomp.)
EXAMPLE 34
Ammonium 4,8-dioxo-4,8-dihydrobenzo-[1,2-b;4,5-b′]dithiophene-2-carboxylate XIV-NH4




Compound XIV (140 mg, 0.53 mmole) was added in IPA (20 mL) and stirred at 60° C. for 30 min. The solid that was not soluble in IPA was filtered. Aqueous ammonium hydroxide (29.5%) was added to the filtrate until basic. After stirring for a while, the solvent was evaporated to yield green-yellow solid XIV-NH4 (68.5 mg, 46%)
1H NMR (500 MHz, CD3OD) δ 7.97 (s, 1H), 7.94 (d, J=5.0 Hz, 1H), 7.64 (d, J=5.0 Hz, 1H).
mp>300° C.
EXAMPLE 35
[(4,8-Dioxo-4,8-dihydroxybenzo[1,2-b;4,5-b′]dithiophen-2-carbonyl)-amino]-acetic acid isopropyl ester XV




To a stirred solution of XIV (244.6 mg, 0.90 mmole) and THF (8 ml) were added isopropyl glycinate HCl salt (140.0 mg, 0.92 mmole), EDC (190.0 mg, 0.99 mmole), HOBt (125.0 mg, 0.93 mmole) and 4-ethylmorpholine (0.12 ml, 0.80 mmole). After stirring at R.T. for overnight under N2, the solvent was removed under reduced pressure. CH2Cl2 (12 ml) was added to the residue and the insoluble solid was removed. The CH2Cl2 layer was then washed with saturated NaHCO3 solution, 1M KHSO4, saturated NaHCO3 solution and H2O. The organic layer was dried over Na2SO4, filtered and concentrated to get crude product. It was purified by column chromatography on silica gel eluting with EA: CH2Cl2 (1:30) to obtain yellow solid XV (75.1 mg, 21%).
1H NMR (500 MHz, CDCl3) δ 7.95 (s, 1H), 7.70 (d, J=5.0 Hz, 1H), 7.65 (d, J=5.0 Hz, 1H), 6.73 (t, J=4.5 Hz, 1H), 5.12 (septet, J=6.5 Hz, 1H), 4.18 (d, J=4.5 Hz, 2H), 1.29 (d, J=6.5 Hz, 6H).
HRMS Calcd for C16H13NO5S2: 363.0235, Found: 363.0228
mp=231.8 ̃233.0° C.
EXAMPLE 36
Methyl (L)-2-{(4,8-Dioxo-4,8-dihydrobenzo-[1,2-b:4,5-b′]dithiophene-2-carbonyl)-amino}propionate XV-1




To a stirred solution of XIV (79.8 mg, 0.30 mmole) in THF (10 ml) were added (S)-alanine methyl ester HCl salt (42.0 mg, 0.30 mmole), EDC (61.0 mg, 0.32 mmole), HOBt (42 mg, 0.30 mmole) and 4-ethylmorpholine (0.04 ml, 0.30 mmole). After stirring at R.T. for overnight under N2, the solvent was removed under reduced pressure. CH2Cl2 (3 ml) was added to the residue and the insoluble solid was removed. The CH2Cl2 layer was then washed with saturated NaHCO3 solution, 1M KHSO4, saturated NaHCO3 solution and H2O. The organic layer was dried over Na2SO4, filtered and concentrated to get crude product. It was purified by column chromatography on silica gel eluting with EA: Hexanes (1:2) to obtain yellow solid XV-1 (38.1 mg, 36%).
1H NMR (500 MHz, CDCl3) δ 7.94 (s, 1H), 7.71 (d, J=5.0 Hz, 1H), 7.65 (d, J=5.0 Hz, 1H), 6.80 (d, J=6.5 Hz, 1H), 4.75 (qd, J=7.5, 6.5 Hz, 1H), 3.80 (s, 3H), 1.53 (d, J=7.5 Hz, 3H).
HRMS Calcd for C15H11NO5S2: 349.0079, Found: 350.0159 (MH+, FAB).
mp=216.8 ̃217.7° C.
EXAMPLE 37
(L)-2-{(4,8-Dioxo-4,8-dihydrobenzo-[1,2-b;4,5-b′]dithiophene-2-carbonyl)-amino}-propionic acid XVI




In a 25 mL flask were placed compound XV-1 (17.6 mg, 0.05 mmole) and MeOH (5 ml). LiOH (45.0 mg) in H2O (4 ml) was then added and reaction mixture stirred at R.T. until hydrolysis completed. HOAc ( ̃0.14 ml) was added drop-wise to neutralize. MeOH was removed under vacuum and the residue was treated with aq. Na2CO3 and then extracted with EA. The aqueous layer was acidified with dilute HCl solution until pH ̃4 and the extracted with EA. The EA layer was dried with Na2SO4, filtered and concentrated to obtain yellow solid XVI (16.8 mg, 99%).
1H NMR (500 MHz, CDCl3) δ 7.96 (s, 1H), 7.62 (d, J=5.0 Hz, 1H), 7.47 (d, J=5.0 Hz, 1H), 4.47 (q, J=7.5 Hz, 1H), 1.36 (d, J=7.5 Hz, 3H).
mp=227.4 ̃228.3° C.
EXAMPLE 38
Sodium (L-2-{(4,8-dioxo-4,8-dihydrobenzo-[1,2-b;4,5-b′]dithiophene-2-carbonyl)-amino}-propionate XVI-Na




To a stirred solution of XVI (73.8 mg, 0.22 mmole) in EA was added sodium 2-ethylhexanoate (1.2 ̃1.5 eq.) in EA and stirred for overnight. The precipitate was filtered and washed with EA and then dried in vacuum. Yellow-green solid XVI-Na (47.5 mg, 60% ) was obtained.
1H NMR (500 MHz, CD3OD) δ 8.25 (s, 1H), 7.96 (d, J=5.0 Hz, 1H), 7.65 (d, J=5.0 Hz, 1H), 4.43 (q, J=7.0 Hz, 1H), 1.48 (d, J=7.0 Hz, 3H).
mp>275° C.
EXAMPLE 39
4,8-dioxo-4,8-dihydrobenzo[1,2-b;4,5-b′]dithiophene-2-carboxylate-(2-dimethylamino-ethyl)-amide XV-2




Compound XIV (0.6086 g, 2.0 mmole), SOCl2 (50 ml) along with a small amount of NaCl was heated to reflux for 2 hrs. The excess SOCl2 was removed and CH2Cl2 was added to the residue. NaCl was filtered and the filtrate was concentrated to yield crude acid chloride (0.5453 g). The acid chloride obtained was used directly without purification. It was diluted with CH2Cl2 (40 ml) and added to the N,N-dimethylethylenediamine (16 ml), Et3N (20 ml) and CH2Cl2 (40 ml) mixture and stirred at R.T. for 12 hrs. Water was added and the reaction mixture extracted with CH2Cl2 The CH2Cl2 layer was concentrated and crude product was purified through column using MeOH: CH2Cl2=1:10 as the eluent. Yellow solid XV-2 (255.2 mg, 33%) was obtained.
1H NMR (500 MHz, CD3OD) δ 8.13 (s, 1H), 7.97 (d, J=5.0 Hz, 1H), 7.65 (d, J=5.0 Hz, 1H), 3.55 (t, J=6.5 Hz, 2H), 2.65 (t, J=6.5 Hz, 2H), 2.37 (s, 6H).
HRMS Calcd for C15H14N2O3S2: 334.0446, Found: 334.0641.
mp=235.5 ̃236.2° C.
EXAMPLE 40
4,8-dioxo-4,8-dihydrobenzo[1,2-b;4,5-b′]dithiophene-2-carboxylate-(2-dimethyl-aminoethyl)-amide phosphoric acid salt XV-2-H3PO4




To a stirred solution of XV-2 (100 mg, 0.30 mmole) in THF was added 85% H3PO4 (1.2 ̃1.5 eq.) and stirred for overnight. The precipitate was filtered and washed with THF and then dried in vacuum. Yellow solid XV-2-H3PO4 (120 mg, 93%) was obtained.
1H NMR (500 MHz, D2O) δ 8.02 (br, 1H), 7.82 (br, 1H), 7.54 (br, 1H), 3.88 (br, 2H), 3.52 (br, 2H), 3.08 (br, 6H).
mp=233° C. (decomp.)
Cytotoxicity Assays Method A (HUVEC, MCF-7, HT-29, Hep 3B and NCl-H460) [S. A. Ahmed, R. M. Gogal Jr., and J. E. Walsh, Journal of Immunological Methods 170: 211-224, (1994): M. R. Boyd, Status of the NCl preclinical antitumor drug discovery screen. (Published by J. B. Lippincoft Company, Philadelphia, Pa. 19105, USA) Principles & Practices of Oncology Updates 3 # 10: 1-12, (1989); M. R. Boyd, et al. Data display and analysis strategies for the NCl disease-oriented in vitro antitumor drug screen. In: Cytotoxic anti-cancer drugs: models and concepts for drug discovery and development. Boston: Kluwer Academic, Pages; 11-34, (1992)]
1. Materials and Equipment
(1) Test Substance and Dosing Pattern
The test compounds were dissolved in 100% DMSO and then diluted with sterile distilled water to obtain initial working solutions of 20000, 2000, 200, 20 and 2 μM in 80% DMSO. A 200 fold dilution was further made in culture media to generate final assay concentrations of 100, 10, 1, 0.1 and 0.01 μM in 0.4% DMSO.
(2) Cell Culture Media











Cell Lines
Culture Medium







HUVEC
Endothelial Cell Growth Medium, 90%; Fetal Bovine



Serum, 10%


MCF-7
Minimum Essential Medium, 90%; Fetal Bovine Serum,



10%


HT-29
McCoy's 5A medium, 90%; Fetal Bovine Serum, 10%


Hep 3B
Minimum Essential Medium, 90%; Fetal Bovine Serum,



10%


NCI-H460
RPMI 1640, 90%; Fetal Bovine Serum, 10%









All of media were supplemented with 1% Antibiotic-Antimycotic.
(3) Cell Lines












Cell Name
Source
Type of Cell Line







HUVEC
ATCC
Human umbilical vein endothelial cells



CRL-1730


MCF-7
ATCC HTB-22
Breast adenocarcinoma, pleural




effusion, human


HT-29
ATCC HTB-38
Adenocarcinoma, colon, moderately




well-differentiated grade II, human


Hep 3B
ATCC HB-8064
Hepatocellular carcinoma, liver, human


NCI-H460
ATCC HTB-177
Large cell carcinoma, lung, human









All of the human tumor cell lines and HUVEC were obtained from American Type Culture Collection (ATCC). The cells were all incubated at 37° C. with 5% CO2 in air atmosphere.

(4) Chemicals

AlamarBlue (Biosource, USA), Antibiotics-Antimycotic (GIBCO BRL, USA), Dimethylsulfoxide (Merck, Germany), Endothelial Cell Growth Medium (CELL APPLICATIONS, INC., USA), Fetal Bovine Serum (HyClone, USA), McCoy's 5A Medium (GIBCO BRL. USA), Minimum Essential medium (GIBCO BRL, USA), Mitomycin (Kyowa, Japan) and RPMI 1640 (HyClone, USA).
(5) Equipment
CO2 Incubator (Forma Scientific Inc., USA), Centrifuge 5810R (Eppendorf, Germany), Hemacytometer (Hausser Scientific Horsham, USA), Inverted Microscope CK-40 (Olympus, Japan), System Microscope E-400 (Nikon, Japan), Spectrafluor Plus (Tecan, Austria) and Vertical Laminar Flow (Tsao Hsin, R. O. C.).
2. Methods
(1) Evaluation of Anti-Proliferative Activity for Test Substances
Aliquots of 100 μl of cell suspension (about 1.5-3.0×103/well) were placed in 96-well microtiter plates in an atmosphere of 5% CO2 at 37° C. After 24 hours, 100 μl of growth medium and 1 μl of test solution or vehicle (80% DMSO) were added respectively per well in duplicate for an additional 72-hour incubation. Thus, the final concentration of DMSO was 0.4%. The test compounds, IIa-1, IIb-1 and VII-1 were evaluated at concentrations of 100, 10, 1, 0.1 and 0.01 μM. At the end of incubation, 20 μl of alamarBlue 90% reagent was added to each well for another 6-hour incubation before detection of cell viability by fluorescent intensity. Fluorescent intensity was measured using a Spectraflour Plus plate reader with excitation at 530 nm and emission at 590 nm.
(2) Determination of IC50, TGI and LC50 
The measured results was calculated by the following formula:

PG(%)=100×(Mean Ftest−Mean Ftime0)/(Mean Fctrl−Mean Ftime0)]

If(Mean Ftest−Mean Ftime0)<0, then

PG(%)=100×(Mean Ftest−Mean Ftime0)/(Mean Ftime0−Mean Fblank)

wherein PG represents percent growth;

Mean Ftime0=The average of 2 measured fluorescent intensities of reduced alamarBlue at the time just before exposure of cells to the test substance;
Mean Ftest=The average of 2 measured fluorescent intensities of alamarBlue after 72-hour exposure of cells to the test substance;
Mean Fctrl=The average of 2 measured fluorescent intensities of alamarBlue after 72-hour incubation without the test substance;
Mean Fblank=The average of 2 measured fluorescent intensities of alamarBlue in medium without cells after 72-hour incubation.
A decrease of 50% or more (≧50%) in fluorescent intensity relative to the vehicle-treated control indicates significant cytostatic or cytotoxic activity, and semi-quantitative values for IC50, TGI and LC50 were then determined by nonlinear regression using GraphPad Prism (GraphPad Software, USA).
IC50 (50% Inhibition Concentration); Test compound concentration where the increase from times in the number or mass of treated cells was only 50% as much as the corresponding increase in the vehicle-control at the end of experiment.
TGI (Total Growth Inhibition): Test compound concentration where the number or mass of treated cells at the end of experiment was equal to that at time0.
LC50 (50% Lethal Concentration): Test compound concentration where the number or mass of treated cells at the end of experiment was half that at time.
Cytotoxicity Assays Method B (HL-60) [H. M. Chen et al. Chin. Pharm. J. 53, 157-167 (2001)]
Cells and Culture
Human promyeloid leukemia HL-60 cells were obtained from the American Type
Culture Collection (Manassas, Va., USA) and the Culture Collection and Research Center(CCRC) (Tai wan, ROC). Human promyeloid leukemia HL-60 cells were cultured in suspension in RPMI-1640 medium (GIBCO, Grand Is land, USA), containing 10% fetal bovine se rum (GIBCO, Grand Is land, USA), 100 unit/mL penicillin, 100 mL/mL streptomycin and 1% L-glutamine at 37° C. in a humidified atmosphere of 5% CO2 in air. Cells were split every day to maintain the cell numbers between 2−5×105/mL. Cell numbers were assessed by the standard procedure of leukocyte counting using a hemocytometer and cell viability was checked by the ability of cells to exclude Trypan blue.
MTT Proliferation Assay
Cellular proliferation was determined by the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] as say. Briefly, 10 mL of MTT (5 mg/mL) was added to each well of 96-well plates containing 1×105 cells after treatment with different concentrations of samples for 4 days. The reaction was stopped after 2 h by adding 100 mL of 0.04 N HCl in isopropanol and the OD570 nm was determined by a minicolorimetric reader. Each concentration treatment was performed in triplicate.
Cytotoxicity Assays Method C (KB, KB-VIN, AS49, HCT-8, PC-3) [K. H. Lee et. al. Planta Med. 54, 308-312 (1998), Monk A et. al. J. Natl. Cancer Inst. 83, 757-766 (1991).] The cell lines included epidermoid caninoma of the nasopharynx (KB), p-gp-expressing epidermoid caninoma of the nasopharynx (KB-VIN), lung carcinoma (A-549), ileocecal carinoma (HCT-8) and prostate cancer (PC-3) cell lines. The cytotoxic effects of each compounds were obtained as IC50 in microgram per ml, the concentration that give 50% inhibition of cell growth after 72 hrs of continuous exposure-variation was less than 5% between replicates.
Anticancer Activity
The assays were used to detect changes in cell proliferation based on the ability of viable cells to cause alamarBlue to change from its oxidized to a reduced form. With the results obtained from the alamarBlue reaction, cell proliferation can be quantified and metabolic activity of viable cell can be examined.
The succinate derivatives of compounds IIa-1, IIb-1 and VII-1 were tested for possible effect on the proliferation of four human tumor cell lines  ̃MCF-7 (breast), HT-29 (colon), Hep3B (liver), and NCl—H 460 (lung) as well as one human umbilical vein endothelial cell (HUVEC) at assay concentration from 0.01 to 100 μM, through serial 10-fold dilution.
The IC50 (50% inhibition concentration), TGI (total growth inhibition) and LC50 (50% lethal concentration) of the three tested compounds were summary in Table 1.
As shown in Table 1, the three tested compounds showed potent cytotoxicity in vitro against NCl—H 460 cell line. Compounds IIa-1 and IIb-1 also had significant activity against MCF-7 and Hep3B cell lines. These two compounds displayed moderate and little activity against HT-29 cell line. Compound VII-1 showed significant cytotoxicity against MCF-7 and Hep3B and moderate activity against HT-29 cell line. On the other hand, all the three tested compounds were essentially inactive or showed little activity in HUVEC assay.
Compound IIa-1-IIa-2-IIb-1-IIb-2-VII-1-VII-2-IX and XV-2-H3PO4 were evaluated for their cytotoxicity in vitro against human promyelocytic leukemia (HL-60) cell line. As shown in Table 2. All of these tested compounds showed significant cytotoxicity. Among them, XV-2-H3PO4 was the most potent one. There fore this compound was selected for further evaluation.
Mono-[1-(4,8dioxo-4,8-dihydrobenzo[1,2-b:5,4-b′]dithiophen-2-yl)-methyl]succinate (IIa-1), mono-[1-(4,8-dioxo-4,8-dihydrobenzo[1,2-b:5,4-b′]dithiophen-2-yl)-methyl]pentanedioate (IIa-2), mono-[1-(4,8-dioxo-4,8-dihydrobenzo[1,2-b:5,4-b′]dithiophen-2-yl)-ethyl]succinate (IIb-1), mono-[1-(4,8dioxo-4,8-dihydrobenzo[1,2-b:5,4-b′]dithiophen-2-yl)-ethyl]pentanedioate (IIb-2), ethyl 4,8-dioxo-4,8-dihydroxybenzo[1,2-b:5,4-b′]-dithiophen-2-yl-methoxy acetate (IVa), mono-[1-(4,8-dioxo-4,8-dihydroxybenzo[1,2-b;4,5-b′]dithiophen-2-yl)-ethyl]succinate (VII-1), mono-[1-(4,8-dioxo-4,8-dihydroxybenzo[1,2-b;4,5-b′]dithiophen-2-yl)-ethyl]pentanedioate (VII-2), 1-(4,8-Dioxo-4,8-dihydroxybenzo[1,2-b:4,5-b′]-dithiophen-2-yl-ethoxy)-acetate (IX), 4,8-dioxo-4,8-dihydrobenzo-[1,2-b;5,4-b′]dithiophene-2-carboxylic acid (XI), 4,8-dioxo-4,8-dihydrobenzo-[1,2-b;4,5-b′]dithiophene-2-carboxylic acid (XIV), 4,8-dioxo-4,8-dihydrobenzo-[1,2-b;4,5-b′]dithiophene-2-carboxylate-(2-dimethylamino-ethyl)-amide phosphate (XV-2-H3PO4), (L)-2-{(4,8-Dioxo-4,8-dihydrobenzo-[1,2-b;4,5-b′]dithiophene-2-carbonyl)-amino}-propionic acid (XVI), and their salts were evaluated for their cytotoxicity in vitro against epidermal carcinoma of the nasopharynx (KB), p-gp-expressing epidermoid carcinoma of the nasopharynx (KB-VIN), lung carcinoma (A-549), ileocecal carcinoma (HCT-8) and prostate cancer (PC-3). As shown in Table 2, Most of these tested compounds showed significant cytotxicity. Among them, XV-2-H3PO4 was the most promising agent. In addition, compounds IIb-1, IIb-2, VII-1 and VII-2 displayed potent activity against the MDR cell line (KB-VIN) and the androgen-insensitive prostate cancer cell line (PC-3). Therefore, compounds XV-2-H3PO4, IIb-1, IIb-2 VII-1 and VII-2 were selected for further pharmacological studies. In summary, the present invention demonstrated remarkable therapeutical potential for benzodithiophenone analogs in the treatment of cancers.
The present invention also discloses a hydrophilic compound having the following structures (F) or (G), or a pharmaceutically acceptable salt thereof:




wherein A3 and A4 independently are —U—C(O)—(CH2)nCOOH, —U—(CH2)n—COOH, —U(CH2)n—NR5R6,





wherein U is O, S, or NH, R5 is H or alkyl; R6 is H or alkyl; and n is 1-5; and Y, Z, R1, R2, R3 and R4 are defined as above.

The present invention also discloses a method for treating a tumor, said method comprising administering to a subject in need of treatment a compound having the formulas (F) or (G) as defined above, or a pharmaceutically acceptable salt thereof, in an amount effective to treat said tumor.







TABLE 1







Cytotoxicity of compounds IIa-1, IIb-1, and VII-1 against MCF7, HT-29, Hep-3B, NCI-H460 and HUVEC cell lines





















 













HUVEC
MCF-7
HT-29
Hep-3B
NCI-H460






















Compounds
IC50a
TGIb
LC50c
IC50a
TGIb
LC50c
IC50a
TGIb
LC50c
IC50a
TGIb
LC50c
IC50a
TGIb
LC50c

























IIa-1
10
19
34
3.4
6.9
14
11
22
45
2.8
5.1
9.2
0.81
1.7
3.5


IIb-1
11
31
89
0.82
4.7
27
4.3
2.0
89
1.1
1.8
2.9
0.64
1.2
2.1


VII-1
11
57
>100
0.96
5.5
31
4.5
38
>100
1.0
1.9
3.4
0.41
1.1
3.0





aIC50 (50% Inhibition Concentration): Test compound concentration μM where the increase from time0 in the number or mass of treated cells was only 50% as much as the corresponding increase in the vehicle-control at the end of experiment.


bTGI (Total growth Inhibition): Test compound concentration μM where the number or mass of treated cells at the end of experiment was equal to that at time0.


cLC50 (50% Lethal Concentration): Test compound concentration μM where the number or mass of treated cells at the end of experiment was half that at time0.













TABLE 2







Cytotoxicity of compounds IIa-1, IIa-2, IIb-1, IIb-2, VII-1, VII-2, IX


and XV-2-H3PO4 against HL-60 cell linea.


















 











Compound
R
IC50 (uM)b







IIb-1
—CH(CH3)—OCO(CH2)2COOH
0.26



IIb-2
—CH(CH3)—OCO(CH2)3COOH
0.25



IIa-1
—CH2—OCO(CH2)2COOH
0.47



IIa-2
—CH2—OCO(CH2)3COOH
0.70



VII-1
—CH(CH3)—OCO(CH2)2COOH
0.26



VII-2
—CH2—OCO(CH2)3COOH
0.28



XVI
—CONHCH(CH3)COOH
0.75



IX
—CH(CH3)OCH2COOH
2.58



XV-2-H3PO4
—CONH(CH2)2N(CH3)2H3PO4
0.05







aHuman promyielocytic leukemia (HL-60).



bIC50 values are the concentration at which 50% of the cells are inhibited from growing.













TABLE 3







Cytotoxicity of compounds IIa-1, IIa-2, IIb-1, IIb-2, IVa, VII-1, VII-2, IX, XI, IV, XV, XVI


and their salts against KB, KB-VIN, A-549, HCF-8 and PC-3 cell lines.

























IC50 (uM)a













Compound
R
KBb
KB-VINc
A549d
HCT-8c
PC-3f





IIb-1
—CH(CH3)—O—CO—(CH2)2COOH
0.47
0.25
0.58
0.91
0.22


IIb-1-Na
—CH(CH3)—O—CO—(CH2)2COONa
0.55
0.47
0.47
1.83
0.37


IIb-2
—CH(CH3)—O—CO—(CH2)3COOH
0.03
0.05
0.11
0.19
0.06


IIb-2-Na
—CH(CH3)—O—CO—(CH2)3COONa
1.36
1.13
1.89
1.89
0.88


IIa-1
—CH2—O—CO—(CH2)2COOH
2.02
4.47
4.03
4.03
1.35


IIa-1-Na
—CH2—O—CO—(CH2)2COONa
2.09
3.79
3.79
3.25
1.22


IIa-2
—CH2—O—CO—(CH2)3COOH
2.22
1.39
2.08
1.66
0.75


IIa-2-Na
—CH2—O—CO—(CH2)3COONa
1.72
1.31
0.94
0.65
0.89


IVa
—CH2—O—CH2COOH
3.61
2.46
2.46
2.07
1.05


XI
—COOH
38.31
38.31
30.27
37.16
13.41


XI-NH4
—COONH4
35.97
35.97
>70
>70
>70


VII-1
—CH(CH3)—OCO—(CH2)2COOH
0.19
0.22
0.47
0.42
0.16


VII-1-Na
—CH(CH3)—OCO—(CH2)2COONa
2.14
1.96
2.22
1.44
0.73


VII-2
—CH(CH3)—OCO—(CH2)3COOH
0.08
0.24
0.51
0.48
0.06


VII-2-Na
—CH(CH3)—OCO—(CH2)3COONa
0.45
0.68
2.52
0.88
0.10


XIV
—COOH
38.31
38.31
44.44
44.06
25.29


XIV-NH4
—COONH4
35.97
35.97
16.19
26.26
13.31


XV-2-H3PO4
—CONH(CH2)2—N(CH3)2—H3PO4
0.06
0.01
0.01
0.01
0.01


XVI-Na
—CONH—C(CH3)COONa
1.76
0.54
0.54
0.51
0.17


IX
—CH(CH3)—O—CH2COOH
19.75
18.18
2.60
0.24
2.51


IX-Na
—CH(CH3)—O—CH2COONa
1.11
1.00
0.26
0.22
0.14












Doxorubincin
0.18
4.97
0.18
NDg
NDg


VP-16
4.76
>10
1.36
NDg
NDg


VCR
0.01
5.33
0.04
NDg
NDg





aIC50 was the concentration of compound which afforded 50% reduction in cell number after 72 hr of incubation.


bepidermoid carcinoma of the nasopharynx (KB).


cp-gp-expressing epidermoid carcinoma of the nasopharynx (KB-VIN).


dlung carcinoma (A-549).


eileocecal carcinoma (HCT-8).


fprostate cancer (PC-3).


gND = Not active at 20 mcq/mL.






The water solubility of some of the synthesized compounds were tested and summarized as below.











Compound
Solubility











9.6 × 10−3 mg/1 mL H2O


1b


 






≧3 mg/1 mL H2O


IIb-1-Na


 






≧9.6 mg/1 mL H2O


IIb-2-Na


 






≧10 mg/1 mL H2O


XI-NH4


 






≧10 mg/1 mL H2O


XI-Na


 






≧2 mg/1 mL H2O


XVII-H3PO4


 






≧6.6 mg/1 mL H2O


XIII-Na


 






≧3.2 mg/1 mL H2O


IVb-Na


 






≧10 mg/1 mL H2O


IIa-1-Na


 






≧1.8 mg/1 mL H2O


IIa-2-Na


 






≧9.6 mg/1 mL H2O


IVa-Na


 






≧10 mg/1 mL H2O


VII-1-Na


 






≧3.4 mg/1 mL H2O


VII-2-Na


 






−4 mg/1 mL H2O


XIV-NH4


 






≧4 mg/1 mL H2O


XV-2-H3PO4


 






≧3.2 mg/1 mL H2O


XVI-Na


 






≧6 mg/1 mL H2O


IX-Na

## Claims

1. A derivative of 4,8-dihydrobenzodithiophene-4,8-dione having the formulas (D) or (E):




wherein Y and Z independently are O, S, —NH— or Se;
A1 and A2 independently are O, S, and NR5, wherein R5 is H or alkyl;
R1, R2, R3, and R4 independently are H, alkyl, —CR5R6—X—C (O)—(CH2)nCOOH, —CR5R6—X—(CH2)nCOOH, —CR5R6—X—(CH2)nNR5R6, —C (O)—NR6—(CR5R6)nCOOH, —C (O)—NR6—(CR5R6)nNR5R6, —CR5R6—C (O)—(CH2)nCOOH, CR5R6—X—C (O)—(CH2)nNR5R6, —C (O)—(CR5R6)nCOOH, —C (O)—(CR5R6)nNR5R6, —CR5═N—(CH2)nCOOH, —CR5═N—(CH2)nCOOH, —CR5═NO, or




wherein X is O, S, or NH; R5 is defined as above; R6 is H or alkyl; and n is 1-5; subject to the proviso that at least one of R1, R2, R3, and R4 is a radical other than hydrogen and alkyl; or a pharmaceutically acceptable salt thereof.

2. The derivative as defined in claim 1, wherein R2, R3 and R4 are H and R1 is —CR5R6—X—C (O)—(CH2)nCOOH, —CR5R6—X—(CH2)nCOOH, —CR5R6—X—(CH2)nNR5R6, —C (O)—NR6—(CR5R6)nCOOH, or —C (O)—NR6—(CR5R6)nNR5R6, wherein XR5, R6 and n are defined as in claim 1.

3. The derivative as defined in claim 1, wherein Y and Z are S.

4. The derivative as defined in claim 2, wherein Y and Z are S.

5. The derivative as defined in claim 1, wherein A1 and A2 are O.

6. The derivative as defined in claim 2, wherein A1 and A2 are O.

7. The derivative as defined in claim 3, wherein A1 and A2 are O.

8. The derivative as defined in claim 4, wherein A1 and A2 are O.

9. The derivative as defined in claim 8, wherein X is O.

10. The derivative as defined in claim 9, wherein R5 and R6 independently are H or methyl.

11. The derivative as defined in claim 10, wherein R1 is —CR5R6—X—C (O)—(CH2)nCOOH.

12. The derivative as defined in claim 10, wherein R1 is —CR5R6—X—(CH2)nCOOH.

13. The derivative as defined in claim 10, wherein R1 is —CR5R6—X—(CH2)nNR5R6.

14. The derivative as defined in claim 10, wherein R1 is —C (O)—NR6—(CR5R6)nCOOH.

15. The derivative as defined in claim 10, wherein R1 is —C (O)—NR6—(CR5R6)nNR5R6.

16. The derivative as defined in claim 10 having the formula (D).

17. The derivative as defined in claim 10 having the formula (E).

18. A compound having the following structures (F) or (G):




wherein A3 and A4 independently are —U—C (O)—(CH2)nCOOH, —U—(CH2)n—COOH, —U—(CH2)n—NR5R6,




wherein U is O, S, or NH; R5 is H or alkyl; R6 is H or alkyl; and n is 1-5; and Y, Z, R1, R2, R3, and R4 are defined as in claim 1, or a pharmaceutically acceptable salt thereof.

19. The derivative as defined in claim 10, which is mono-[1-(4,8-dioxo-4,8-dihydrobenzo[1,2-b;5,4-b′]dithiophen-2-yl)-methyl]succinate, mono-[1-(4,8-dioxo-4,8-dihydrobenzo[1,2-b:5,4-b′]dithiophen-2-yl)-ethyl]succinate, or mono-[1-(4,8-dioxo-4,8-dihydrobenzo[1,2-b:5,4-b′]dithiophen-2-yl)-ethyl]pentanedioate;
mono-[1-(4,8-dioxo-4,8-dihydroxybenzo[1,2-b;4,5-b′]dithiophen-2-yl)-ethyl]succinate, mono-[1-(4,8-dioxo-4,8-dihydroxybenzo[1,2-b;4,5-b′]dithiophen-2-yl)-ethyl]pentanedioate, or 4,8-dioxo-4,8-dihydrobenzo[1,2-b;4,5-b′]dithiophene-2-carboxylate-(2-dimethylamino-ethyl)-amide.