In the 50 years that have elapsed sirice the pioneeriiig work of Watanabel on the hypoglycemic activity of guanidine, a large number of substituted guanidine;, have been synthesized and evaluated for their eff ectiveriess in lowering blood sugar concentration. While the lower alkyl derivatives, l-methylguaiiiditi(~ and 1,l-dimethylguanidirie, are completely devoid of activity, isoamylguanidine niid isoamyleneguariidiiic (Galegine) are more active than guanidine itself. Wlieii the alkylguariidiiiea are bubstituted by a terminal basic' moiety as in 4-aniinobutylguanidiiie (Agmatiii) a i i t l decamethylenediguanidirie (Synthalin), potent hypoglycemic agents are obt:tined. On the other hand, the, terminal carboxy-substituted conipouiids, exemplified by w-guanidinoalkanoic acids, are inactive. The report that w-guanidinoallianoic esters (1:i j :tnd amides (Ib) are useful therapeutic agent3 for the treatment of diabetes3 :tnd that y-guanidinohutyramide pohsesses potent hypoglycemic mtivity in animals4 prompted us to explore the hypoglyceniic activity of a series of w-gua1iidiiioalkaiioI~(IC),theii esters (Id), and their carbamates (le). Certnin nicmbers of these series were found to possess marked hypoglycemic activity when :idministered to rats :m(l rat)hitb. Our interest in iubstitutetl hydroxylmiines l d u. to csterid this study t o include a variety of w - g u a i i i diiiooxydliaIio1~and w-gunnidinoox?-alli:tiioic acids : i n d their derivatives (11). In t l i i b manuscript 11 e report tIic syiithes sugar lowering activity of the-c gunnidiiio aiid guuiiidiiiooxy compouiids.
The guariidino:tlk~iiiols(IC)werc o btairied by treating the corresponding nmirioa1li:iiiol~ with 2-methyl-2thiopseudouren. Conrw.ioii of the guariidi~ioalkariol salts to their esters (Id) arid carbamate derivatives (Ie) was accomplished using 5t:mclard procedures, and no interaction between the acylating agent and the gu:ini( 1 ) ('. i i . I T a t a n a l i ~d, . B i d . C'hem., 33, 2 5 3 (IUIX).
( 2 ) E'nr a cornpreliensive revierr of the literature on liypoirlyceniio Knanidines. see 11.. Creutzfeldt and 11. Srjling. Ergeb. I n n . M e d . K i n d e r h e i l k . , 15, 1 ilHBO). ( 3 ) Iiorlicks Ltd., French Patent 5 i l ) W. J . 11. lintterfirld. 13. 11. a t ~ I i e1~:iiropean.issociation fur 611 24, 1 Y i j X .
I . .I. ~ \ ~ l i i c l i ~Iiauer l o ~ ~ presentmi , betea. I.ouvain, July 2 2
HYPOGLYCEMIC GUANIDINE nERIV.4TIVES
January 1970
G1
TABLE I GUANIDISOALKANOLS AND DERIVATIVES NH H2&H(CH2).li. KO.
n
x
Salt
l a
2 2 2 3 3 3 3 3
OH OCONH? OSO3H OH OCOCHI 0C0C 6H 3 OCONH2 OCOK(CzH,)z
HzSOa HC1
2 3 40
5 6 7 8
HC1 HCl HC1 HC1 HC1
Mp,
Recrystn solvent
oc
132-133 125-128 201-204 80-82 78-80 143-14.5 122-124
AcOH
z-P~OH E tOH-HLO i-PrOH-JIeiCO Et OH-E ti0 2-PIOH 2-PrOH
C
Formula
Analyses
CsHzoNeO6S C4HiiClNaOi CaHgK304S C~HizClX30 CsHiaC1x@? C,iHi&l?J,O? COHi3ClX40i CgHnClS40i
C, H, N, S C, H, C1, S C, H, N , s
C, H, C1, N C, H, C1, N C, H , C1, N C, H, C1, N C, H, C1, N
1
OCON(CHi), HCl C 9 3 CgHigClN;402 C, H, C1, K 10 3 OSOBH 179-181 EtOH-H 2 0 C4HuS30,S C, H, N, S 11b 4 OH HC1 107-1 09 2-PrOH CDHi4C1N30 C, H, C1, ?r' HCl C 12 4 OCOCHI C;HI,C~N~OZ C, H, C1, N 13 4 OCOCeH5 HCl 111-113 7-PrOH CizHixClNDL C, H, C1, X 14 4 OCONHi HC1 180-1 83 i-PrOH C6H,5Cl?i40* C, H, C1, N HC1 C 15 4 OCONHCH3 CTHi+2lN40r C, H, C1, S 16 4 OCOSHCHI CHdd 123-126 t-PrOH Ci3H?gNa05S C, H, pi, S a Reported by Schering-Kahlbaum A-G, German Patent 462,995 (1928). The correkponding nitrate and picrate -alts are dehcribed.7 c Noncryatallizable liquid. d Cyclohexanesulfamate salt.
GU.4NIDINOOXY
TABLE 11 ALKANOLS, ALKANOICACIDS, AND DERIVATIVES NH
I'
H2N&KHO(CH2),X NO.
n
17 18 19 20 21 22 23 24 25 26 27 28 29 30
1 2 3 3 3 3 3 3 3 3 3 3 4 4
X
COOH OH COOH COOCHI COXH2 OH
OH OCOCH3 OCONHz OCONHCHa OCON(CHs)z OCOKC4HxO' COOH
OH
alp,
oc
195-1965 102-103 207-208. jC 77-79 109.5-1 11 108-1 09 109-111 108.5-110 152-153 138-138.5 1.51.5-1.52 07-98 192-195 80 5-81.5
0 Lit.* mp 195'. Cyclohexanesulfamate salt. c Lit.8 mp 205". N : calcd, 22.12; found, 22.45. J XCIHsO = morpholino.
pound was dissolved in saline and injections were made subcutaneously. Blood samples were obtained before administration of the compound and 2.5 and 5 hr after drug injection. Phenformin was used as positive control. Blood glucose was measured by the Hoffman procedure as modified for the Technicon Auto-Analyze$ Graded doses of compound were employed, and the concentration producing a significant lowering of blood glucose at 2.5 or 5 hr mas determined. Of the 30 compounds evaluated, six were equal or superior to y-guanidinobutyramide when evaluated in the rat and five in the rabbit (see Table 111). The remaining compounds failed to produce a significant lowering of blood sugar in rats at 300 mg/kg and in rabbits at 400 mg/kg after subcutaneous administration. (5) W. S. Hoffman, J . Biol. Chem.. 120, 51 (1937). We thank Drs. J. F. Douglas and H. Singer for these determinations.
Recrystn solvent
Me2CO-HZO z-PrOH-hIe2CO Hi0 i-PrOH-Eta0 z-P~OH i-PrOH-?\Ie&O z-PrOH-MeOH EtOH 1IeOH-EtOH
RIeOH-EtOAc
Formula
Analyses
CgH22N405S C, H, N, S C, H, ,hu' C,HIINIOB C6H14ClS303 C, H, C1, N, OCH3 CiiH?aKu'jO,S C, X, S; Hd Cl~H~4N40iS C, H, N, S C X H Z ~ N ~ O ~ S C, H, pi, S CiiHixNs0mS C, H, N, S C I O H Z ~ N X ~ I O S C, H, pi, S C1zH3&sOloS C, H, N, S C I ~ H ~ ~ N S O ~ ~ C, S S;H , Ne CljH31N607S C, H, K, S C, H, N C&N303 CiiHs&408 C, H, N, S
RIeOH-EtOAc z-PrOH-i-PrSO HzO 2-PrOHi-PrzOEtOAc d H : calcd, 7.42; found, 6.95.
e H : calcd, 6.77; found, 6.31.
3-Guanidinooxypropanol sulfate (23) was the most potent compound when evaluated in the rat and approximated phenformin in its activity. In the rabbit, 4-guanidinobutyl methylcarbamate hydrochloride (15) exhibited the greatest activity.
Experimental Section6 w-Guanidinoalkano1s.-2-Guanidinoethanol sulfate (1) was obtained in 67y0 yield from 2-aminoethanol and 2-methy1-2thiopseudourea sulfate. 3-Guanidinopropanol hydrochloride (4) and Pguanidinobutanol hydrochloride (11) were prepared in 79 and 84y0 yields, respectively, essentially by the method of Fishbein and Gallaghan.7 (6) hlelting points were determined using a Thomas-Hoover melting point apparatus and are uncorrected. Analyses were performed by Galbraith Laboratories, Inc., Knoxville, Tenn. 37921. Where analyses are indicated only by symbols of the elements, analytical results obtained for these elements were within &0.370 of the theoretical values. (7) L. Fishbein and J. -4. Gallaghan, J . Am. Chem. Soc., 76, 3217 (1954).
.January 1970
63
HYPOGLYCEMIC GUANIDINE DERIVATIVES
was concentrated Zn vacuo. The residue was taken up in CHC13, and the solution was filt'ered and coriceiitrated in vacuo, leaving crude 2-(aminooxy)et8hanolas an oil. The aminooxy compound (39 g), 135 g of 2-methyl-2-thiopseudourea cyclohexaiiesulfamate (preparation follows), and 1 1. of EtOH were refliixed for 13 hr. The cooled mixt,ure was filtered and the filtrate was evaporated in L'UCUO. Compound 18 was crystallized by addition of 3.50 ml of i-PrOH. Filtrat,ion and addition of i-PrlO to the filtrate provided a secoud crop, The product was purified by bririgirig the crude yield to 30';. recrystallizat,ion. 3-(Guanidinooxy)propanol cyclohexanesulfamate (22) was prepared in the same manner as described for 19, except that the crude 3-(phthalimidooxy)propanol, after removal of the S a B r aiid DMF, was poiired iiito HyOarid solidified. It was separated from a n oily contaminant by extractiou into hot CC14 from which it cryptallized on cooling. 3-(Phthalimidooxy)propanol, reAnal. (Cllcrystallized from i-Pr20, melted a t 85.5-86.5'. H;i?;OA) C, H, S. 3-(Guanidinooxy)propanolSulfate (23).-3-(Phtha1imidooxy)propanol was converted to 3-(aminooxy)propaiiol as described above for 2-(aminooxy)ethariol. The aminooxypropanol (57 g), 89 g of 2-methyl-2-thiopseudoiirea sulfate, and 400 ml of HzO were heated o n a steam bath for 2 hr. Unchanged t,hiouroriium salt TYas removed by concentrating the reactioii mixture in vacuo, dissolving t,he residue in 100 ml of JIeOH, arid filtering. The MeOH was removed in uacuo and the residue was extracted with hot CGH6, EtZO, arid i-PrOH. The product was cryst,allized from LIeOH-i-PrOH. 3-(Guanidinooxy)propyl Acetate Sulfate (24)-3-(Phthaliniidooxy)propniic)l (38 g), 38 ml of AcyO, aiid 228 ml of pyridiiie were refluxed for 5 min, cooled, and poiired onto 760 g of ice. Concentrated HC1 (235 ml) \\-as added to precipitate the acetate. It, was filtered off, washed ( H 2 0 ) )aiid converted, withoiit piirification, to 3-(aminooxy)propyl acetate as described for the preparation of 18. This was converted t o 3-(guaiiidinooxy)propyl acetate sulfate by the method described for 23. A portion of 3-(phtha1imidooxy)propyl acetate, recrystallized Anal. (C13H13XO5) from CC14-hexane, had m p 61.5-63.5'.
C, H, K. A portion of 3-(aminooxy)propyl acetate was converted to its HCl salt, m p 79-82' (i-PrOH-EtzO). A n a l . (CjHIzClSO,) C, HI C1, N. 4-(Guanidinooxy)butanol Cyelohexanesulfamate (30).-4(Phtha1imidooxy)butyl benzoate was prepared from S-hydroxyphthalimide arid 4-bromobutyl benzoateI2 by the procedure described for the preparatioii of 19 except that' the crude product,, after removal of D N F , was poured into H 2 0 and allowed to solidify. Recrystallized (GPrOH) 4-(phtha1imidooxy)butyl beiizoate had m p 84-85.5'. Anal. (C,,H,iKO5) H, N ; C: calcd, 67.25; fourid, 67.94. This was converted to 4-(aminooxy)butyl benzoate by t'he procedure described for the preparation of 18. A solut,ion of t,he crude 4-(aminooxy)butyl benzoate (from 0.2 mole of phthalimidooxy compound) in 400 ml of AleOH, to which 160 mg of RIeOSa had been added, was refluxed for 9 hr and concentrated in uacuo, and the residue was dissolved in CHC13. The solution was freed of MeONa by filtration and t,he solvent was removed in vuczm. The crude residual 4-(aminooxy)butanol was separated from methyl benzoate by extraction into H20, evaporation i n vacuo, and drying by azeotropic distillat,ion with C ~ H G .The 4-(aminooxy)butaiiol was coiiverted to 30 by the method described for 18. 3-(Guanidinooxy)propyl Carbamate Sulfate (25).-3-(Phthalimidooxy)propyl carbamate was prepared from S-hydroxyphthalimide aiid 3-chloropropyl carbamate13 by the procedure described for the preparation of 30, mp 134-13.5" ii-PrOH, CnH6). Anal. (CiZHisNsOa)C, H, N. The phthalimidooxy compound yielded 3-(aminooxy)propyl carbamat,e by the hydrazinolysis procedure described for the preparation of 18. The aminooxy compound was purified by conversion to its hydrochloride with ethanolic HCl, mp 127-128" (i-PrOH, BuOH). Anal. (Cl4Hi,ClNzO3) C, H, C1, N. The amiriooxy compound, liberated from the hydrochloride as described in the preparation of 19, was converted t,o 25 by the method described for 23. 3-(Guanidinooxy)propyl Methylcarbamate Sulfate (26).h T H F solution of 3-bromoprop2-1 chloroformate was treated with (12) J. B. Cloke and F. J. Pilgrim, J . A m . Chem. Soc., 61, 2667 (1939). (13) A . W.Doxand L. Yoder, zbid., 46, 723 (1923).
2 equiv of M e S H p in T H F and the amine salt was filtered off. The filtrate was concentrated in wacuo and the crude 3-bromopropyl methylcarbamate was used to alkylate K-hydroxyphthalimide as described for the preparation of 19. 3-(Phthalimidooxy)propyl methylcarbamate, recrystallized from Et0.4~i-PrzO, melted a t 99-100.5". Anal. ( C I ~ H ~ ~ NC, ~O H,SN. ) Crude 3-(aminooxy)propyl methylcarbamat'e, obtained from the pht,halimidooxy compound by the procedure described for 18, was converted to 3- (guanidino0xy)propyl methylcarbamate cyclohexariesulfamate by t,he procedure described for 23, using 2methyl-2-thiopseudourea cyclohexanesulfamate instead of the sulfate. When all att,empts to crystallize the cyclohexaiiesulfamate failed, the free guanidinooxy base was liberated with MeONa in i-PrOH as described for the preparation of 19, dissolved in H 2 0 , and adjusted to pH 5.0 by addition of aqueous H2S04. The solution was Concentrated in vacuo and 26 was crystallized iri 167, yield. 3-(Guanidinooxy)propyl Dimethylcarbamate Sulfate (27).A T H F soliit,ioii of 78.3 g of 3-chloropropyl chloroformate XYas treated with 121 g of 40c7, (w/w) aqueous RleaSH with cooling, the solution \vas concentrated in vacuo, arid the residual carbamate was t,akeii up iii EtOAc, washed (2c0HC1, aqueous iYaHC03, H20),and dried (l;azSO1). The crude 3-chloropropyl dimet,hylcarbamate after removal of t,he solvent was used to alkylate S-hydroxyphthalimide as described for the preparation of 19. The crude 3-(phtha1imidooxy)propyl dimethylcarbamate n-as extracted t,hree times with i-Pr,O, the extracts x-ere discarded, and the insoluble oil was treated with N2H1.HzO as described for t,he preparation of 18. The crude 3-(aminooxy)propyl dimet,hylcarbamate was purified by conversion to the sulfate, mp 148-149" from EtOH-2'-PrOH. Anal. (CIzH3ON4OioS) C, H, N, S. An aqueous solution of the sulfate was treated with 1 equiv of Ba(OH)*'8H20 and t,hen converted t,o 27 via the cyclohexanesulfamate as described for t'he preparation of 26. 3-(Guanidinooxy)propyl 4-Morpholinecarboxylate Cyclohex4-morpholinecarboxylate anesulfamate (28).-3-Bromopropyl was prepared from 3-bromopropyl chloroformate and 2.5 equiv of 40yc aqueous morpholiiie as described for the preparation of 27. The solvent was removed in c'acuo and replaced by i-PrsO. Ethaiiolic HC1 was added arid the mixture v a s filtered. The filtrate was washed with H20, dried (RlgSOd), aiid evaporated in e~acvo. The residiial crude bromocarbamate was converted by the procedure described for 30 to 3-(phtha1imidooxy)propyl 4-morpholinecarboxylate, mp 96-97" (hexane-CC14). Anal. (Ci~HiaN206)C, H, N. The phthalimidooxy compoiind was converted to 28 by the procedure described for 18. 2-Methyl-2-thiopseudourea Cyclohexanesulfamate.--4 solutioii of 27.3 g of Ba(OH)*.8H20in 70 ml of hot H20 was mixed with a solution of 27.8 g of 2-methyl-2-thiopseudourea sulfat,e in 150 ml of H 2 0aiid the mixture was st'irred for 45 min, then filtered with the aid of Celite. The filtrate was concentrated in C'QCUO, MeOH was added to the residue, and the evaporation was repeated. A hot solutioii of the residue in 50 ml of RIeOH was treated with a hot solution of 35.8 g of cyclohexanesulfamic acid in 60 ml of MeOH and chilled, and the cyclohexanesulfamate salt was filtered off, mp 172.5-175' from EtOH. Anal. (CaHi~N303Sz)C, H, N, S. Reaction of Ethyl 4-(Phtha1imidooxy)butyrate with NH3 in Me0H.-Ethyl 4-(phtha1imidooxy)butyrate (13.9 g) was dissolved in 30 ml of RleOH and 50 ml of 6.5 3" in MeOH was added. The mixture was filtered free of phthalamide (identified by mp and ir) after 1.5 hr at room temperatiire. The filtrate was coiirentrated in vacuo arid the residue was treated with 50 ml of C6Hs. Ilore pht.halamide was filtered from this solution and the filtrate was once again concentrated in vacuo, yielding 4.5 g (61%) of crude et'hyl 4-(aminooxy)butyrate, which was converted t o its hydrochloride, m p 105-108", lit.14 mp 106-107". A \ -
Acknowledgment.-The authors are greatly indebted to Dr. F. M. Berger for making available the result's of the biological evaluations. Assistance by Xrs. Ru-jen Lee Han, Blr. Alexander G. Korzun, and Nr. William J. Bowling in the preparation of a number of compounds described in this paper is also acknowledged. (14) R . XI. Khomutov, hl. Ya. Karpeiskii, and S a u k S S S R , Otd. Kkim. N a u k , 1074 (1962).
E. 6. Severin, Ira. Akad.
