United States Patent [19J
`Schiehser
`
`[54] FLUORINATED ESTERS OF RAPAMYCIN
`
`[75]
`
`Inventor: Guy A. Schiehser, Yardley, Pa.
`
`[73] Assignee: American Home Products
`Corporation, New York, N.Y.
`
`[21] Appl. No.: 682,793
`
`[22] Filed:
`
`Apr. 8, 1991
`
`Int. CI.s ..................... A61K 35174; C07D 491/14
`[51]
`[52] U.S. Cl ..................................... 514/183; 514/321;
`540/456
`[58] Field of Search ................. 540/456; 514/183, 321
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`3,929,992 12/1975 Sehgal et al ........................ 424/122
`3,993,749 11/1976 Sehgal et al. ....................... 424/122
`4,316,885 2/1982 Rakhit ................................. 424/122
`4,401,653 8/1983 Eng ..................................... 424/114
`4,650,803 3/1987 Stella et al. ........................... 546/90
`4,885,171 12/1989 Surendra et al. ................... 424/122
`
`OTHER PUBLICATIONS
`J. Antibiot. 28, 721-726, 727-732 (1975).
`J. Antibiot. 31, 539-545 (1978).
`Can. J. Physiol. Pharrnacol. 55, 48 (1977).
`FASEB 3, 3411, 5256 (1989).
`Lancet pp. 1183-1185 ( 1978).
`Med. Sci. Res. 17:877 (1989).
`
`Primary Examiner-Robert T. Bond
`Attorney. Agent, or Firm-Arnold S. Milowsky
`
`ABSTRACT
`[57]
`A compound of the structure
`
`I lllll llllllll Ill lllll lllll lllll lllll lllll 111111111111111111111111111111111
`US005100883A
`5,100,883
`[11] Patent Number:
`[45] Date of Patent: Mar. 31, 1992
`
`wherein
`RI and R2 are each, independently, hydrogen or
`
`R3 is a mono-, di-, poly-, or per-fluorinated alkyl
`group with the proviso that RI and R 2 are both not
`hydrogen, which by virtue of its immunosuppres(cid:173)
`sive activity is useful in treating transplantation
`rejection, host vs. graft disease, autoimmune dis(cid:173)
`eases and diseases of inflammation; by virtue of its
`antitumor activity is useful in treating solid tumors;
`and by virtue of its antifungal activity is useful in
`treating fungal infections.
`
`11 Claims, No Drawings
`
`Breckenridge Exhibit 1011
`Breckenridge v. Novartis AG
`
`

`
`1
`
`5,100,883
`
`2
`RI and R2 are each, independently, hydrogen or
`
`R 3 is a mono-, di-, poly-, or per-fluorinated alkyl
`group of 1-10 carbon atoms; with the proviso that
`RI and R2 are both not hydrogen.
`Of these compounds, preferred members are those in
`which R2 is hydrogen; those in which R3 is a mono-, di-,
`poly-, or per-fluorinated alkyl group of 1-6 carbon
`atoms; and those in which R2 is hydrogen and R3 is a
`mono-, di-, poly-, or per-fluorinated alkyl group of 1-6
`carbon atoms.
`The compounds of this invention acylated at the
`42-position can be prepared by acylating rapamycin
`with an acylating agent having the general structure
`
`0
`II
`XCR 3
`
`FLUORIJ'liATED ESTERS OF RAPAMYCIJlil
`
`10
`
`BACKGROUND OF THE INVENTION
`This invention relates to novel esters of rapamycin 5
`and a method for using them in the treatment of trans(cid:173)
`plantation rejection, host vs. graft disease, autoimmune
`diseases, diseases of inflammation, solid tumors, and
`fungal infections.
`Rapamycin is a macrocyclic triene antibiotic pro-
`duced by Streptomyces hygroscopicus, which was found
`to have antifungal activity, particularly against Candida
`albicans, both in vitro and in vivo [C. Vezina et al., J.
`Antibiot. 28, 721 (1975); S. N. Sehgai et al., J. Antibiot. 15
`28, 727 (1975); H. A. Baker et al., J. Antibiot. 31, 539
`(1978); U.S. Pat. No. 3,929,992; and U.S. Pat. No.
`3,993,749].
`Rapamycin alone (U.S. Pat. No. 4,885,171) or in com(cid:173)
`bination with picibanil (U.S. Pat. No. 4,401,653) has 20
`been shown to have antitumor activity. R. Martel et al.
`[Can. J. Physiol. Pharmacol. 55, 48 (1977)] disclosed
`that rapamycin is effective in the experimental allergic
`encephalomyelitis model, a model for multiple sclerosis;
`in the adjuvant arthritis model, a model for rheumatoid 25
`arthritis; and effectively inhibited the formation of IgE(cid:173)
`like antibodies.
`The immunosuppressive effects of rapamycin have
`been disclosed in F ASEB 3, 341 I ( 1989). Cyclosporin A
`and FK-506, other macrocyclic molecules, also have 30
`been shown to be effective as immunosuppressive
`agents, therefore useful in preventing transplant rejec(cid:173)
`tion [FASEB 3, 3411 (1989); FASEB 3, 5256 (1989); and
`R. Y. Caine et al., Lancet 1183 (1978)].
`Mono- and diacylated derivatives of rapamycin (es- 35
`terified at the 28 and 43 positions) have been shown to
`be useful as antifungal agents (U.S. Pat. No. 4,316,885)
`and used to make water soluble prodrugs of rapamycin
`(U.S. Pat. No. 4,650,803). Recently, the numbering
`convention for rapamycin has been changed; therefore 40
`according to Chemical Abstracts nomenclature, the
`esters described above would be at the 31- and 42-posi(cid:173)
`tions.
`
`where X is OH, in the presence of a coupling reagent,
`such as CMC (l-cyclohexyl-3-(2-morpholinoethyl)car(cid:173)
`bodiimide metho-para-toluenesulphonate). The com-
`pounds of this invention also can be prepared by using
`an anhydride of the above described carboxylic acid as
`the acylating species. In addition, the acylating species
`can be an acid halide, where X can be Cl, Br, or I.
`Alternatively, reagents such as Ishikawa's Reagent
`(N,N-diethyl-1, 1-2,3,3,3-hexafluoropropylamine)
`can
`be used as an acylating reagent to give compounds of
`this invention.
`The compounds of this invention acylated at both the
`31- and 42-positions can be prepared by the methods
`described above by increasing variables such as reaction
`time, temperature, and quantity of acylating agent.
`The 31-acylated compounds of this invention can be
`prepared by protecting the 42-alcohol of rapamycin
`with a protecting group, such as with a tert-butyl dime(cid:173)
`thylsilyl group in the presence of a base, such as imidaz(cid:173)
`ole, followed by acylation of the 31-position with an
`acylating agent having the general structure shown
`45 above. Removal of the protecting group provides the
`31-acylated compounds. In the case of the tert-butyl
`dimethylsilyl protecting group, deprotection can be
`accomplished under mildly acidic conditions, such as
`with a mixture of aqueous acetic acid and THF.
`50 Having the 31-position acylated and the 42-position
`deprotected, the 42-position can be reacted with a dif(cid:173)
`ferent acylating agent than was reacted with the 31-
`alcohol, to give compounds having different acyl moi(cid:173)
`eties at the 31- and 42-positions. Alternatively, the 42-
`55 acyl compounds, prepared as described above, can be
`reacted with an acylating agent having a different struc(cid:173)
`ture to provide compounds having different acyl moi(cid:173)
`eties at the 31- and 42-positions.
`The acylating groups used to prepare the compounds
`60 of the invention are commercially available or can be
`prepared by methods that are disclosed in the literature.
`Immunosuppressive activity was evaluated in an in
`vitro standard pharmacological test procedure to mea(cid:173)
`sure lymphocyte proliferation (LAF) and in two in vivo
`65 standard pharmacological test procedures. The first in
`vivo procedure was a popliteal lymph node (PLN) test
`procedure which measured the effect of compounds of
`this invention on a mixed lymphocyte reaction and the
`
`DESCRIPTION OF THE INVENTION
`This invention provides derivatives of rapamycin
`which are useful as immunosuppressive, anti-inflamma-
`tory, and antifungal agents having the structure
`
`~OR 1
`
`-~~-OM'.
`~o
`
`0
`
`OMe
`
`wherein
`
`

`
`3
`second in vivo procedure evaluated the survival time of
`a pinch skin graft.
`The comitugen-induced thymocyte proliferation pro(cid:173)
`cedure (LAF) was used as an in vitro measure of the
`immunosuppressive effects of representative com- S
`pounds. Briefly, cells from the thymus of normal
`BALB/c mice are cultured for 72 hours with PHA and
`IL-1 and pulsed with tritiated thymidine during the last
`six hours. Cells are cultured with and without various
`concentrations of rapamycin, cyclosporin A, or test
`compound. Cells are harvested and incorporated radio(cid:173)
`activity is determined. Inhibition of lymphoprolifera(cid:173)
`tion is assessed as percent change in.counts per minute
`from non-drug treated controls. The results are ex- IS
`pressed by the following ratio, or as the percent inhibi(cid:173)
`tion of lymphoproliferation at 1 µM.
`
`5,100,883
`
`4
`The following table summarizes the results of repre(cid:173)
`sentative compounds of this invention in these three
`standard test procedures.
`TABLE 1
`PLN•
`LAP
`(ratio)
`(ratio)
`
`Compound
`
`Skin Graft
`(days+ SD)
`
`10
`
`Example I
`Example 2
`Example 3
`Example 4
`Rapamycin
`
`40
`2.3
`27
`14.8
`I
`
`1.28
`1.03
`0.23
`0.96
`I
`
`10.33 ::!:: 1.0
`12.0 ::!:: 1.3
`+
`+
`12.0 ::!:: 1.7
`
`•CaJculauon of rattos was described supra.
`;- Not evaluated
`
`3H-control thymus cells - Hl-rapamycin-treated thymus cells
`3H-control thymus cells - Hl·tcst compound-treated cells
`
`2S
`
`A mixed lymphocyte reaction (MLR) occurs when
`lymphoid cells from genetically distinct animals are
`combined in tissue culture. Each stimulates the other to
`undergo blast transformation which results in increased
`DNA synthesis that can be quantified by the incorpora(cid:173)
`tion oftritiated thymidine. Since stimulating a MLR is a
`function of disparity at Major Histocompatibility anti(cid:173)
`gens, an in vivo popliteal lymph node (PLN) test proce- 30
`dure closely correlates to host vs. graft disease. Briefly,
`irradiated spleen cells from BALB/c donors are in(cid:173)
`jected into the right hind foot pad of recipient C3H
`mice. The drug is given daily, p.o. from Day 0 to Day
`4. On Day 3 and Day 4, tritiated thymidine is given i.p., 3S
`b.i.d. On Day 5, the hind popliteal lymph nodes are
`removed and dissolved, and radioactivity counted. The
`corresponding left PLN serves as the control for the
`PLN from the injected hind foot. Percent suppression is
`calculated using the non-drug treated animals as allo- 40
`genie control. Rapamycin at a dose of 6 mg/kg, p.o.
`gave 86% suppression, whereas cyclosporin A at the
`same dose gave 43% suppression. Results are expressed
`by the following ratio:
`
`3H-PLN cells control C3H mouse -
`3H-~LN cells rapamycin-treated C3H mouse
`H-PLN cells control C3H mouse -
`lH-PLN cells test compound-treated C3H mouse
`
`The second in vivo test procedure is designed to
`determine the survival time of pinch skin graft from
`male DBA/2 donors transplanted to male BALB/c
`recipients. The method is adapt:d from Billingham R. SS
`E. and Medawar P. B, J. Exp. Biol. 28:385-402, (1951).
`Briefly, a pinch skin graft from the donor is grafted on
`the dorsum of the recipient as a bomograft, and an
`autograft is used as control in the same region. The
`recipients are treated with either varying concentra- 60
`tions of cyclosporin A as test control or the test com(cid:173)
`pound, intraperitoneally. Untreated recipients serve as
`rejection control. The graft is monitored daily and ob(cid:173)
`servations are recorded until the graft becomes dry and
`forms a blackened scab. This is considered as the rejec- 6S
`tion day. The mean graft survival time (number of
`days±S.D.) of the drug treatment group is compared
`with the control group.
`
`The results of these standard pharmacological test
`procedures demonstrate immunosuppressive activity
`both in vitro and in vivo for the compounds of this
`invention. Positive ratios in the LAF and PLN test
`procedures indicate suppression of T cell proliferation.
`20 As a transplanted pinch skin grafts are typically re(cid:173)
`jected within 6-7 days without the use of an immuno(cid:173)
`suppressive agent, the increased survival time of the
`skin graft when treated with the compounds of this
`invention further demonstrates their utility as immuno(cid:173)
`suppressive agents.
`Because the compounds of this invention are structur(cid:173)
`ally similar to rapamycin and have a similar activity
`profile to rapamycin, the compounds of this invention
`also are considered to have antitumor and antifungal
`activities.
`Based on the results of these standard pharmacologi(cid:173)
`cal test procedures, the compounds are useful in the
`treatment of transplantation rejection such as, heart,
`kidney, liver, bone marrow, and skin transplants; auto(cid:173)
`immune diseases such as, lupus, rheumatoid arthritis,
`diabetes mellitus, myasthenia gravis, and multiple scle-
`rosis; and diseases of inflammation such as, psoriasis,
`dermatitis, eczema, seborrhea, inflammatory bowel
`disease; solid tumors; and fungal infections.
`The compounds may be administered neat or with a
`pharmaceutical carrier to a mammal in need thereof.
`The pharmaceutical carrier may be solid or liquid.
`A solid carrier can include one or more substances
`which may also act as flavoring agents, lubricants, solu-
`4S bilizers, suspending agents, fillers, glidants, compression
`aids, binders or tablet-disintegrating agents; it can also
`be an encapsulating material. In powders, the carrier is
`a finely divided solid which is in admixture with the
`finely divided active ingredient. In tablets, the active
`SO ingredient is mixed with a carrier having the necessary
`compression properties in suitable proportions and
`compacted in the shape and size desired. The powders
`and tablets preferably contain up to 99% of the active
`ingredient. Suitable solid carriers include, for example,
`calcium phosphate, magnesium stearate, talc, sugars,
`lactose, dextrin, starch, gelatin, cellulose, methyl cellu-
`lose, sodium carboxymethyl cellulose, polyvinylpyr(cid:173)
`rolidine, low melting waxes and ion exchange resins.
`Liquid carriers are used in preparing solutions, sus(cid:173)
`pensions, emulsions, syrups, elixirs and pressurized
`compositions. The active ingredient can be dissolved or
`suspended in a pharmaceutically acceptable liquid car(cid:173)
`rier such as water, an organic solvent, a mixture of both
`or pharmaceutically acceptable oils or fats. The liquid
`carrier can contain other suitable pharmaceutical addi(cid:173)
`tives such as solubilizers, emulsifiers, buffers, preserva-
`tives, sweeteners, flavoring agents, suspending agents,
`thickening agents, colors, viscosity regulators, stabiliz-
`
`

`
`5,100,883
`
`0
`
`5
`6
`mg of dimethylaminopyridine and IOI mg (140 µI, 1
`ers or osmo-regulators. Suitable examples of liquid car-
`mmol) of triethylamine in 50 ml of methylene chloride
`riers for oral and parenteral administration include
`water (partially containing additives as above, e.g. eel-
`is treated dropwise with 114 mg (1 mmol, 77 µI) of
`trifluoroacetic acid. The mixture is maintained with
`Julose derivatives, preferably sodium carboxymethyl
`cellulose solution), alcohols (including monohydric 5 stirring for 17 h. An additional 1 mmol of CMC, 20 mg
`of dimethylaminopyridine, 1 mmol of triethylamine and
`alcohols and polyhydric alcohols, e.g. glycols) and their
`1 mmol of trifluoroacetic acid is added. Additional
`derivatives, and oils (e.g. fractionated coconut oil and
`arachis oil). For parenteral administration, the carrier
`trifluoroacetic acid (1 mmol) is added at 0.5 h intervals
`can also be an oily ester such as ethyl oleate and isopro-
`until conversion is complete.
`pyl myristate. Sterile liquid carriers are useful in sterile JO
`The mixture is diluted with water and ethyl ether and
`liquid form compositions for parenteral administration.
`is extracted with ethyl ether. The ethereal extract is
`The liquid carrier for pressurized compositions can be
`washed with water, 0.5N hydrochloric acid and finally
`halogenated hydrocarbon or other pharmaceutically
`with saturated aqueous sodium bicarbonate. The solu-
`acceptable propellent.
`.
`Liquid pharmaceutical compositions which are sterile
`tion is dried over magnesium sulfate, filtered and evapo-
`solutions or suspensions can be utilized by, for example, 15 rated to give 870 mg of a white foam. The crude prod-
`uct is subjected to flash chromatograph~ using hex-
`intramuscular, intraperitoneal or subcutaneous injec-
`tion. Sterile solutions can also be administered intrave-
`ane:ethyl ether (1 :4) as the eluant. The obtamed product
`nously. The compound can also be administered orally
`to af-
`is recrystallized fro~ hexane:cyclohexane !1:1)
`either in liquid or solid composition form.
`20 ford 397 mg of the title compound: m.p. 88 -91 C.
`Preferably, the pharmaceutical composition is in unit
`Anal. Calcd. for Cs3H78F3N014: C, 63.02; H, 7.78; N,
`1.39. Found: C, 63.21; H, 7.67; N, 1.34.
`dosage form, e.g. as tablets or capsules. In such form,
`the composition is sub-divided in unit dose containing
`The following representative compounds can be pre-
`appropriate quantities of the active ingredient; the unit
`pared from rapamycin and the appropriate carboxylic
`dosage forms can be packaged compositions, for exam- 25 acid by employing Method B used to prepare the title
`pie, packeted powders, vials, ampoules, prefilled syrin-
`compound in Example 1.
`ges or sachets containing liquids. The unit dosage form
`Rapamycin, 42-ester with perfluorovaleric acid
`can be, for example, a capsule or tablet itself, or it can be
`Rapamycin, 42-ester with perfluorodecanoic acid
`the appropriate number of any such compositions in
`Rapamycin, 42-ester with perfluorooctanoic acid
`package form. The dosage to be used in the treatment 30 Rapamycin, 42-ester with 9-H perfluorononanoic acid
`must be subjectively determined by the attending physi(cid:173)
`EXAMPLE2
`cian.
`In addition, the compounds of this invention may be
`Rapamycin, 42-ester with 2,3,3,3-tetrafluoropropanoic
`employed as a solution, cream, or lotion by formulation
`acid
`with pharmaceutically acceptable vehicles containing 35
`To a solution of 914 mg (1 mmol) of rapamycin in 20
`0.1-5 percent, preferably 2%, of active compound
`ml of methylene chloride is added 245 mg ( 1.1 mmol) of
`which may be administered to a fungally affected area.
`Ishikawa Reagent (N,N-diethyl 1,1,2,3,3,3-hexafluoro(cid:173)
`The following examples illustrate the preparation of
`propylamine). After 1 hr, an additional 84 mg (0.4
`representative compounds of this invention.
`mmol) of Ishikawa Reagent is added. The mixture is
`40 stirred for 2 h and then is diluted with ethyl ether and
`aqueous sodium bicarbonate. The ethyl ether layer is
`separated and the aqueous layer is reextracted with
`ethyl ether (2 times). The combined ethereal extracts
`are dried over magnesium sulfate, filtered and removed
`of solvent in vacuo to give 762 mg of a solid foam.
`A portion of the crude product is subjected to silica
`gel chromatography using hexane:ethyl ether (1 :4) as
`the eluant to give 310 mg of product (Rf=0.28 hex(cid:173)
`ane:ethyl ether(l :4)). Recrystallization from hexane:cy(cid:173)
`clohexane (3:1) gives, after high vacuum drying over
`phosphorus pentoxide, 246 mg of the title compound:
`m.p. 87° -90° C.;
`Anal. Calcd. for CS4ff79F.N014: C, 62.23; H, 7.64, N,
`1.34. Found: C, 62.97; H, 7.69; N, 1.07.
`
`EXAMPLE 1
`Rapamycin, 42-ester with trifluoroacetic acid
`Method A
`To a solution of 274 mg (0.3 mmol) of rapamycin in
`10 ml of methylene chloride is added 63 mg (0.3 mmol, 45
`43 µI) of trifluoroacetic anhydride and then 39 mg (0.3
`mmol) of diisopropylethylamine (Hunig's base). The
`mixture is stirred for 30 min and then an additional 78
`mg (0.6 mmol, 106 µl) ofHunig's base is added followed
`by 63 mg (43 µI, 0.3 mmol) oftrifluoroacetic anhydride. 50
`After 30 min the reaction mixture is diluted with
`ethyl ether and aqueous sodium bicarbonate. The mix(cid:173)
`ture is extracted with ethyl ether (3 times) and the com(cid:173)
`bined organic extracts are washed with aqueous sodium
`bicarbonate. The resulting extract is dried over magne- 55
`EXAMPLE 3
`sium sulfate and removed of solvent in vacuo to give a
`solid foam.
`Rapamycin, 42-ester with difluoroacetic acid
`Flash chromatography on silica gel using ethyl
`ether:hexane (4:1) as the eluant gave 96 mg of product
`A solution of914 mg (1 mmol) ofrapamycin, 846 mg
`which is recrystallized from cyclohexane:hexane (1:1) 60 (2mmol)ofCMC,40mgofdimethylaminopyridineand
`to give 68 mg of the title compound: m.p. 87°-91° C.
`202 mg (280 µI, 2 mmol) of triethylamine in 50 ml of
`Anal Calcd. for C53H7gF3N014: C, 63.02; H, 7.78; N,
`methylene chloride is treated dropwise with 192 mg
`1.39. Found: C, 62.85; H, 7.84; N, 1.41.
`(126 µl, 2 mmol) of difluoroacetic acid. The mixture is
`maintained with stirring for 1 h and additional triethyl-
`65 amine and difluoroacetic acid is added until the conver(cid:173)
`sion is complete.
`The mixture is diluted with water and ethyl ether and
`is extracted with ethyl ether. The ethereal extract is
`
`Method B
`A solution of914 mg (I mmol) ofrapamycin, 423 mg
`(I mmol) of CMC (l-cyclohexyl-3-(2-morpholinoe(cid:173)
`thyl)carbodiimide metho-para-toluenesulphonate), 20
`
`

`
`5,100,883
`
`7
`washed with water, 0.5N hydrochloric acid and finally
`with saturated aqueous sodium bicarbonate. The solu(cid:173)
`tion is dried over magnesium sulfate, filtered and evapo(cid:173)
`rated to give a white foam. The crude product is crys(cid:173)
`tallized from cyclohexane to give 703 mg product.
`Flash chromatography using hexane:ethyl ether(l :4) as
`the eluant followed by recrystallization from cyclohex(cid:173)
`ane affords the title compound: m.p. 87'-89' C.
`Anal. Calcd. for Cs3H79F2N014: C, 64.16; H, 8.03; N,
`1.41. Found: C, 64.46; H, 8.05; N, 1.42.
`
`8
`3. A compound of claim l where R3 is a mono-, di-,
`poly-, or per-fluorinated alkyl group of 1-6 carbon
`atoms.
`4. A compound of claim 1 where R2 is hydrogen and
`S R3 is a mono-, di-, poly-, or per-fluorinated alkyl group
`of 1-6 carbon atoms.
`S. A compound of claim 1 which is rapamycin, 42-
`ester with trifluoroacetic acid.
`6. A compound of claim 1 which is rapamycin, 42-
`10 ester with 2,3,3,3-tetrafluoropropanoic acid.
`7. A compound of claim 1 which is rapamycin, 42-
`ester with difluoroacetic acid.
`8. A compound of claim 1 which is rapamycin, 42-
`ester with pentafluoropropionic acid.
`9. A method of treating transplantation rejection,
`host vs. draft disease, autoimmune diseases, and diseases
`of inflammation in a mammal by administering an effec(cid:173)
`tive amount of a compound having the formula
`
`EXAMPLE4
`Rapamycin, 42-ester with pentafluoropropionic acid
`A solution of914 mg (l mmol) ofrapamycin, 846 mg IS
`(2 mmol) of CMC, 40 mg of dimethylaminopyridine and
`202 mg (280 µ.l, 2 mmol) of triethylamine in 50 ml of
`methylene chloride is treated dropwise with 328 mg
`(210 µ.I, 2 mmol) of pentafluoropropionic acid. The
`mixture is maintained with stirring for I h and addi- 20
`tional triethylamine and difluoroacetic acid is added
`until the conversion is complete.
`The mixture is diluted with water and ethyl ether and
`is extracted with ethyl ether. The ethereal extract is
`washed with water, 0.5N hydrochloric acid and finally 25
`with saturated aqueous sodium bicarbonate. The solu(cid:173)
`tion is dried over magnesium sulfate, filtered and evapo(cid:173)
`rated to give a white foam. The crude product is crys(cid:173)
`tallized from cyclohexane to give 703 mg product.
`Flash chromatography using hexane:ethyl ether (1:4) as 30
`the eluant followed by recrystallization from hexane:cy(cid:173)
`clohexane (1: 1) affords the title compound: m.p. 90' -97'
`c.
`Anal. Calcd. for CS4H78FsN014: C, 61.18; H, 7.42; N,
`1.32. Found: C, 61.45; H, 7.42; N, 1.33.
`What is claimed is:
`l. A compound of the formula
`
`3S
`
`wherein
`RI and R2 are each, independently, hydrogen or
`
`40
`
`4S
`
`so
`
`SS
`
`wherein
`RI and R2 are each, independently, hydrogen or
`
`R3 is a mono-, di-, poly-, or per-fluorinated alkyl
`group of 1-10 carbon atoms; with the proviso that
`RI and R2 are both not hydrogen.
`2. A compound of claim 1 where R2 is hydrogen.
`
`60 R3 is a mono-, di-, poly-, or per-fluorinated alkyl group
`of 1-10 carbon atoms; with the proviso that RI and R 2
`are both not hydrogen.
`10. A pharmaceutical composition for use as an im(cid:173)
`munosuppressive agent comprising an immunosuppres-
`6S sive amount of a compound of claim l.
`11. A composition as claimed in claim 10 in unit dos(cid:173)
`age form.
`• • • • •