284 BARGER AND EWINS:XXX.-The Alkaloids of Brgot. Part 1%By GEORGE BARGER and ARTHUR JAMES EWINS.IN a previous communication on this subject (Trans., 1907, 91,337), oue of us, in conjunction with F. H. Carr, described thenew amorphous alkaloid ergotoxine, C,,H,,O,N,, and assigned t oTanret’s crystalline ergotinine the formula C,H,,O,N,. Thecrystalline alkaloid was thus proved to be the anhydride of theamorphous one, as was first surmised by Kraft.*The transformation of ergotoxine into ergotinine takes place byboiling with methyl alcohol (Kraft), or with acetic anhydride.When, on the other hand, ergotinine was warmed on the water-bath with very dilute phosphoric acid, Barger and Carr obtainedfrom it the crystalline phosphate of an amorphous base, whichclosely resembled ergotoxine phosphate in physiological action andhad the same melting point; the crystalline form was, however,entirely different. Ergotoxine phosphate crystallises in thin needles(Fig.2), the new phosphate formed rhomb-shaped, triangular, orhexagonal plates (Fig. l), and the difference persisted after thebases had been liberated, dissolved in ether, and again convertedinto their phosphates by precipitation with alcoholic phosphoricacid.We have now found the cause of this difference between the twosalts. When ergotinine is heated with a solution of phosphoricacid in ethyl alcohol, there is formed, not ergotoxine phosphate,but the phosphate of ergotoxine ethyl ester, and it is the lattersalt which crystallises in plates.The hydrochlorides of the twobases are also quite different (Figs. 3 and 4). That the new base* The identity of Kraft’s hydroergotinine (Arch. Pharm., 1906, 244, 336) withergotoxine was recently doubted by Vahlen (Arch. e q . Path. Phnrm., 1908, 60, 42)on physiological grounds, but an analysis of hydroergotinine sulphate by Kraft(Arch. Pharm. , 1907, 245, 644) and a comparative physiological examination byDale (Arch. exp. Path. Phnmt., 1909, 61, 113) leave no doubt that hydroergotinineand ergotoxine are synonymous termsTHE ALKALOIDS OF ERGOT. PART 11. 285is an ethyl ester was shown by analysis, and especially by a deter-mination of the ethoxy-group by Zeisel’s method.It thus follows that ergotoxine contains a carboxyl group, andthat ergotinine is its lactone (or lactam).I n accordance with thisview, ergotoxine is soluble in sodium hydroxide, but ergotinine isnot, nor is the ester-base above referred to. Esterification probablytakes place to some extent when ergotoxine is boiled with alcohol(in the absence of phosphoric acid). We have noticed repeatedlyin converting ergotoxine into ergotinine by boiling with methylalcohol (Kraft’s method) that the yield is far from quantitative;some of the ergotoxine is probably converted by this process intothe very soluble ethyl ester, instead of the crystalline anhydride. Itis, moreover, quite likely that ergotinine itself when boiled withalcohol forms ergotoxine ester to some extent; this behaviour wouldexplain the loss of ergotoxine on recrystallisation which we our-selves and others (Tanret, Meulenhoff) have noticed.The fall inoptical rotatic n shown by alcoholic ergotinine solutions, especiallyon boiling, is also probably due t o the formation of an ergotoxineester.Besides proving the presence of a carboxyl group in ergotoxine,we have been able to establish the presence of a somewhat largerand more characteristic fragment of the complicated molecule ofthe ergot alkaloids. On destructive distillation, both ergotoxine andergotinine yield a small quantity of a crystalline substance, andthis we have been able to identify as isobutyrylformamide,CHMe,*CO*CO*NH,. The yield of this substance is only 5 percent. of the (very costly) alkaloid employed; as we had only afew decigrams of the substance a t our disposal, its identificationwas somewhat troublesome, but was finally rendered certain bydirect comparison with a specimen of isobutyrylformamide syn-thesised for the purpose.A ketonic amide of this type does not appear to have beenpreviously obtained from a natural substance, and we are unableto suggest the mechanism of its formation from the ergot alkaloids.We do not think, however, that either of the oxygen atoms of theamide belongs t o the carboxyl group which we have shown to bepresent in ergotoxine.If this be admitted, we have accounted forfour out of the six oxygen atoms of that alkaloid (or three out ofthe five present in ergotinine). The two remaining oxygen atomsare not present as phenolic hydroxy- or methoxy-groups, becauseergotinine is insoluble in sodium hydroxide, and when examinedby Zeisel’s method yields a negative result.One of the nitrogenatoms probably has a methyl group attached to it, because some286 BARGER AND EWINS:thing like one equivalent of methyl iodide is set free whenergotinine is examined by Herzig and Meyer's method. At leastone of the five nitrogen atoms is tertiary, for a methiodide is slowlyformed. It is remarkable that, in spite of having five nitrogenatoms, the ergot alkaloids are only very feeble mono-acid bases.EXPERIMENTAL.Phosphate of Ergot oxine E't hyl Ester, C34H4004N5* C0,*C,H5,H3P0,.One gram of crystalline ergotinine was suspended in 10 C.C. ofabsolute ethyl alcohor; and 1.1 equivalent of phosphoric acid dis-solved in 5 c .~ . of alcohol was added. On warming on the water-bath for fifteen to thirty minutes, the ergotinine gradually dis-solved ; on cooling, an amorphous solid separated, which witscollected' and crystallised from 90-95 per cent. ethyl alcohol. Inthis way about 0.3 gram of a grey product was obtained, whichFIG. 1. FIG. 2.UPhosphate of ergotoxine ethyl ester. Ergotoxine phosphate.x 65 diameters. x 65 diameters.on recrystallisation from 1 2 C.C. of 95 per cent. alcohol separatedin almost white leaflets (Fig. 2), melting at 187-1880 (bath pre-viously heated to 180°). For the sake of comparison the crystallineform of ergotoxine phosphate is shown in Fig. 2. These and theother figures were drawn from micro-photographs :0.1353 gave 0.2922 CO, and 0*0812 H,O. C = 58.9 ; H = 6.4.C37H450,N,,H3P0, requires C = 58.9 ; H = 6.4 per cent.C3,H,,06N5,H3P.04 ,, C = 57.9 ; H = 6.1 ,,As the phosphate of an ethyl ester of ergotoxine contains only1 per cent,.more carbon than that of the corresponding ergotoxinesalt, a direct deterinination of the ethoxy-group was made by Zeisel'smethod THE ALKALOIDS OF ERGOT. PART 11. 2870.3503 gave 0.1064 AgI.C34H4,0,N,*C02Et,H,P04 requires OEt = 5-97 per cent.The rotation of this salt was also determined in 75 per cent.alcohol. Z = 1 dcni.; c=2*03; ctD + 1 . 5 8 O ; [a], +77*8O. From thephosphate obtained in the manner described, the base was set freeby sodium carbonate, dissolved in ether, and dried with sodiumsulphate.From the ethereal solution of the base obtained in thisway, the hydrochloride and the oxalate were precipitated by addingalcoholic hydrochloric acid and ethereal oxalic acid solutions respec-tively.OEt =5.82.Hydrochloride of Ergo toxine Etlql Ester, C3,H4,0,N,,HC1.The precipitated salt crystallised from 90 per cent. alcohol inlarge plates (Fig. 3), which melted at 206-207° (bath previouslyheated to 190.). For the sake of comparison, crystals of ergotoxinehydrochloride (m. p. ZO5O) are shown in Fig. 4.*The difference in crystalline form existing between salts ofergotoxine and the corresponding salts of the ethyl ester is alsoclearly shown is the case of the oxalates formed by adding anFIG. 3. FIG. 4.Hydrochloride of ernotoxine ethyl ester.x 65 &meters.Ergotoxinc hydrochloride.x 65 diameters.ethereal solution of oxalic acid to the bases dissolved in ether.Both salts melt a t 179-180°, but whereas the ergotoxine oxalateforms elongated, rectangular prisms, the salt of the ester crystallisesin hexagonal leaflets.By warming ergotinine with a solution of phosphoric acid inmethyl alcohol, crystalline salts of ergotoxine methyl ester arereadily obtainable.As in the case of the ethyl ester, this base is* I n the previous paper (Trans., 1907, 81, 350) it was stated that ergotoxine hgdro-chloride forms ‘‘ diamond-shaped plates and very thin and very long, square-endedneedles. ” The plates, however, were an adinixtnre of the hydrochloride of ergotoxineethyl ester288 RARGER AND EWINS:amorphous, thus resembling ergotoxine ; the ester bases differ,however, from ergotoxine in being insoluble in dilute sodiumhydroxide.Salts of Ergotoxine.In addition to the phosphate, the hydrochloride, and the twooxalates of ergotoxine, which were described in the earlier paper,several other salts have been obtained crystalline.They wereprepared in each case by adding a dilute ethereal or alcoholicsolution of the acid to a solution of ergotoxine in ether, until nofurther precipitate wa-s formed. The precipitated salt wz19 driedin a vacuum, and crystallised from warm 90 to 95 per cent. alcohol.Not infrequently the salt separates as a jelly on cooling; in suchcases it is best to dilute the solution, so that nothing separates oncooling, and then to add a few drops of dry ether at intervals.Ergotoxine picrate forms pale yellow, acicular prisms, meltingat 214-215O (bath first heated t o 210O):0.1536 gave 17.2 C.C.N2 (moist) a t 10'5O and 757 mm.Ergotoxine hydrobromide, acicular prisms, melting at 208O :0.1042 gave 0.0260 AgBr. Br=10'6.Ergotoxine sulphate, prisms, melting at 197O :0.1192 gave 0.0358 BaSO,.This appears to be a somewhat impure acid sulphate; thatErgotoxime nitrate forms short, broad prisms, melting atN=13*2.C&&,O6N&6H&&Ns requires N = 13.1 per cent.C,H,,O,N,,HBr requires Br = 11.3 per cent.H,SO,= 12.6.C3,H4,O6N,,H,80, requires H,SO, = 13.5 per cent.prepared by Kraft was the normal one.193-194'.Action of Methyl Iodide o n Ergotinine, Ergotoxine, and ErgotoxineEsters.Ergotinine and allied Gases appear to have one tertiary nitrogenatom.Ergotinine dissolves readily in methyl iodide, but when thesolution is left at the laboratory temperature for some days, it isgradually transformed into a white jelly, readily soluble in alcohol;this jelly doubtless represents the methiodide. Ergotoxine and itsesters behave in a similar way, except that the reaction is morerapid. In no case, however, could a crystalline product be isolated.We give as an example the analysis of the precipitate formed ina solution of ergotoxine methyl ester in methyl iodide; the sub-stance, presumably the methiodide, was washed with dry ether anddried a t loooTHE ALKALOIDS OF ERGOT. PART 11.2890.1300 gave 0.0365 AgI. I= 15.2.C36H4,0,N,,CH31 requires I = 16.2 per cent.Action of Absolute 9Zcohol on Ergotinine.A sohtion of 0.24 gram of crystalline ergotinine in 100 C.C. ofabsolute ethyl alcohol was divided into two portions. A 2-2-dcm.polarimeter tube was filled with one portion of the solution, andkept in the dark at the laboratory temperature for some months.During this time the rotation gradualy decreased,, as shown by thefollowing table :a,. 1. [a],.June 11 th + 1 *76" 2'2 clcm. + 333"June 12th f 1 . 7 1 2.2 2 2 + 324June 14th + l - 6 6 2.2 2 ) + 314June 17th +1%1 2.2 > s + 305July 19th + 1'52 2'2 J > + 290June 28th + 1-61 2-52 2 2 + 305Sept. 13th + 0'62 1 2 ) -!- 258The other portion was heated under a reflux condenser on thewater-bath ; here the change was more rapid :Time in hours.a D .0 +1*76"1 + 1-594 + 1 '41 a+ + 0'67154 + o-al23 + 0'5930 + 0.4837 + 0.371. [ale-2.2 dcm. + 333"2 2 2 + 3312 2 9 + 2942 1) + 2751 2 t + 2541 1 ) + 2461 2 ) + 2001 ? ) + 154In boiling alcoha,,.: solution t-e c .ange is even more rapid. Asaturated solution prepared by shaking a t loo gave:Z=2*2 dcm.; ~=0*2566; aD+1*9l0; [ u ] ~ +338O.After boiling for five minutes, [a], fell to 3 2 7 O , after one hourCrystals of ergotinine, obtained by rapidly cooling a boilingto 300°, after three hours to 2 4 2 O .alcoholic solution, are shown below :FIG. 5.VOL. XCVII.Ergotinine. x 65 diameters..290 EARCIER AND EWINS:Isolation of iEjoButyryIforrnarnide on Destructhe Distillation.of theErgot AIkaloas.The formation of a crystalline sublimate can be observed bycarefully heating a few milligrams of ergotinine or ergotoxine init small tube. The alkaloids melt and decompose, and a minutequantity of a colourless liquid appears in the cold part of the tube;this soon crystallises, and if the operation is carried out underdiminished pressure the substance appears a t once in glisteningleaflets.It was soon found that the substance, once set free, sublimes a tlooo, and cannot be recrystallised from organic solvents withoutgreat loss. I t s purification was therefore carried out by sub-limation under diminished pressure.Ergotinine (in some cases ergotoxine) was heated in quantities of0.5 gram a t a time in a flask of 6-10 C.C.capacity, which was pro-vided with a neck 25 cm. long and 1 cm. wide. Almost the whole ofthe bulb could be immersed in a metal-bath at 220-240O; the lowerpart of the neck, adjoining the bulb, was jacketed with steam, andthe flask was evacuated to 2 mm. pressure. By this means thecrystalline sublimate collected only on the upper part of the neck,above the steam-jacket. It wits contaminated with a little yellowoil, and was purified as follows. The region of the tube wherethe sublimate had condensed was cut off, placed in it test-tube, andthe substance re-sublimed in a boiling water-bath under a pressureof 15 to 20 mm.; it condensed on the upper portion of the test-tube,from which it was removed by means of a glass rod.In this way0.09 gram of pure sublimate was obtained from the base from3 grams of somewhat impure exgotoxine phosphate ; in anotherexperiment, 0.5 gram of pure ergotinine yielded 0.021 gram ofsublimate, or 4.2 per cent.As thus obtained, the substance formed thin, large, glisteningleaflets, melting in a sealed tube a t logo, readily soluble in coldalcohol, but only sparingly so in cold water and in benzene:0.0467 gave 0.0881 CO, and 0.0325 H,O.0.0860 ,, 8.8 C.C. N, (moist) at 19O and 767 Rim. N=12*0.C,H,O,N requires C = 52.1 ; H = 7.8 ; N = 12.2 per cent,The vapour-density was determined by Victor Meyer's method :0.091.3 gave 22-05 C.C. moist air at 17O and 762 mm.C,H,O,N= 115 requires V.D. =57.5.Although the percentage of carbon found is rather low, theAt first we foundC = 51.1 ; H = 7.4.0.1034 ,, 0.1946 CO, ,, 0.0756 H2O. C=51.3; H=8.1.V.D.=53.formula C,HDO,N is established with certaintyTHE ALKALOIDS OF ERGOT. PART 11. 291several per cent. too much nitrogen, until we employed cuprouschloride (compare Haas, Trans., 1906, 89, 570). The same difficultywas experienced by Barger and Carr in determining the nitrogenin ergotinine (Trans., 1907, 91, 343, footnote), and is apparentlydue to the presence of a gem-dimethyl group, resulting in theformation of methane. We have now actually located this dimethylgroup in isobutyrylformamide, where, on analysis by Dumas'smethod, unless cuprous chloride or lead chromate is used, it producesa much larger error than when accompanied by the rest of themolecule in ergotinine.Some of this methane probably alsoescaped combustion in the carbon and hydrogen estimations quoted.The melting point of our substance corresponded closely withthree substances of the formula C,H,O,N described in the literature,namely, butyrylformamide, isobutyrylf ormamide, and lzvulinamide.We first prepared butyrylformamide by the method given below.This substance was found to have a striking resemblance to thesublimate from the ergot alkaloids, and melted a t 1OSo, but onmixing with this substance the melting point was 89-90O. Wenext prepared isobutyrylformamide, which again was quite similarin its properties. It melted at 107-108°, and this time the meltingpoint remained unchanged, when the synthet,ic was mixed with thenatural substance.The melting points may be tabulated thus :1. Butyrylformarnido, 108". Mixture of 1 and 2, 88-89",2. isoBur yrylforinaniide, 107-108". Mixture of 1 and 3, 89-90".3. Sa1)stsnc.e from ergot alldoids, 109". Mixture of 2 arid 3, 107-10s".In addition, the vapours of 2 and 3 readily gave, on gentlewarming, tlie pyrrole reaction with a pinewood splint moistenedwith hydrochloric acid, but 1 gave only a doubtful coloration onstrongly heating.The sublimate from the ergot alkaloids is therefore isobutyryl-formamide, CHMe,*CO*CO.NET,.In addition to this substance we obtained, on destructive dia-tillation of the alkaloids under 2 mm. pressure, a small quantity ofa base boiling a t 88-89O, which was condensed in a tube cooledby carbon dioxide and acetone, and had an odour like pyrrolidine.The substance left in the flask was somewhat volatile under 2 mm.pressure, and crept up the sides of the flask as an amber-coloured,viscid liquid, but could not be distilled.Synthesis of Butyryl and isoButyryEforrnarnide.Moritz (Trans., 1881, 39, 14) prepared butyryl and isobutyryl-cyanide from the corresponding chlorides and silver cyanide.Wefound the yield to be very unsatisfactory, and therefore adoptedClaisen's method (Ber., 1S98, 3 1, 1023), using anhydrous hydrogenu 292 CHATTAWAY AND CHANEY :cyanide. 12.5 Grams of butyryl chloride were added to a solutionof 3-2 grams of hydrogen cyanide in 46 C.C. of dry ether, and tothe well-cooled solution 10 C.C. of pyridine were slowly added.After standing overnight, the pyridine hydrochloride, which ha,dseparated, was removed by filtration. The ethereal filtrate waswashed with 5 per cent. sulphuric acid to remove the pyridine, andthen with water to remove the acid. After drying, the etherealsolution was evaporated, and the residue distilled, when 1 gramof butyrylcyanide was obtained ; the rest of the reaction productconsisted mostly of the bimolecular polymeride. By hydrolysis with85 per cent. sulphuric acid, 0.4 gram of butyrylformamide wasobtained. It was purified by sublimation from a boiling-waterbath under diminished pressure, and melted in a sealed tube a t 108O(Moritz found 105-106°). isoButyrylformamide was prepared inthe same way, and melted a t 107-108°. As stated above, this sub-stance, unlike the normal amide, on heating, readily gives thepyrrole reaction with pinewood. Its melting point is given byMoritz (erroneously) as 125--126O, by Brunner (flfonatsli., 1894,15, 758) as 10G-107°, and by Friinke and Kohn (Monatsh., 1899,20, 887) as l l O o .We desire to acknowledge our indebtedness to Messrs. E. T.Thompson and S. M. Pettet, who have respectivelyc made the micro-photographs and drawings, from which the figures of crystals havebeen prepared.THE WELLCOME PHYSIOLOGICAL R ESEAXCH LABORATORIES,RROCKWELL HALL, HERNE HILL, LONDON, S.E