411 XXXIIL-The Action of Isothiocyanates on the Aldehyde-amnzonias. By AUG. E. DIXON M.D. Assistant Lecturer in Chemistry Trinity College University of Dublin. Acetaldehyde-ammonia is known to combine with certain of the “mustard-oils; ” thus R. Schiff (Ber. 9 565) has described corn-pounds obtained by the action of the former on ethyl- allyl- and phcnyl-thiocarbimides respectively. Some time ago happening to have in my possession a quantity of benzylthiocarbimide I tried its action on acetaldehyde-ammonia ; with the result that the two substances readily combined under the following conditions :-1 mol. of benzylthiocarbimide dissolved in a small quantity of strong alcohol was mixed with a concentrated alcoholic solution of 2 mols. of aldehyde-ammonia. The mixture was gently warmed on the water-bath and in a few minutes solid matter began to separate ; on removing the dish from the water-bath the contents almost immediately set to a white crystalline mass.This was drained on +he filter-pump and pressed between filter-paper. It was then shaken up with cold spirit and again drained and pressed. On care-fully recrystallising the product from hot absolute alcohol a woolly mass of white shining needles was obtained which was dried over sulphuric acid under the air-pump receiver. The substance is sparingly soluble in cold alcohol; it dissolves tolerably freely in boiling alcohol by which however it is gradually decomposed with evolution of ammonia and aldehyde. It is insoluble in water sparingly soluble in ether and bisulphide of carbon more easily in chloroform.Benzene when hot dissolves it moderately but when cold very sparingly. It melts at 175” with browning and copious evolution of gas. The alcoholic solution is slowly desulphurised by boiling with alkaline lead tartrate ;* wit,h excess of silver nitrate a white precipitate separates which on standing quickly blackens. Ammoniacal silver nitrate gives a yellow precipitate which blackens on boiling. The substance was found to contain carbon hydrogen nitrogen, and sulphur. On analysis the following data were obtained :-0.2192 gram burnt with lead chromate gave 0.1507 H,O and 0.4966 coz, or C = 61.78 H = 7.66. f Described by Emerson Reynolds Trans. 1884 162. 2 F 412 DIXON THE ACTION OF ISOTHIOCYAKATES 0.2230 gram gave 0,5042 GO (hydrogen lost), 0.3344 gram burnt with soda-lime gave 0.4208 Pt, 0.2492 gram fused with EazC03 + KC103 gave 0.2358 BaS04, or C = 61-65.or N = 18.13 per cent. or S = 13.01 per cent., from which the formula G121817N3S is deduced. ~~ ~ 421 143.64 . H, 17-00 . N3 42.03 . S 31.98 . 234 *65 Theory. -61 -21 7 -24 17 -91 13 *62 99.98 -~ Experiment. I. 1 11. i- -I - -The reaction may be represented thus :-C,H7*NCS + 2CzH40,NH3 = C12HI7N3S + 2HzO. This decomposition recalls the observation made by Nencki (Bey. 7, 162) that thiocarhamide and aldehyde-ammonia unite with elimina-tion of water and NH3 :-CS(NH,)2 + 2C,H,O,NH = CsHiIN3S + NH3 + HZO. Nencki considers the compound C5Hl,N3S to be an ammonia-derivative of diethylidenethiocarbamide CS (N C2H4), and writes its formula- cs C2H,)N2,NHs0 CzH4 J From the mode of formation of this compound we may suppose group to exist in i t ; and the decomposition may be the represented thus :-‘X< .. . . . . . . -in ,/ sc + . . ‘ H N< :H + 2H,O + NH3 ON THE ,4LDEHYDE-AMMONIAS. 413 We may suppose now that in the case of benzylthiocarbimide the NH3 which 2 mols. of aldehyde-ammonia can afford (as above), instead of being evolved is fixed by the thiocarbimide forming, perhaps for the moment benzylthiocarbamide which then reacts with the aldehyde-ammonia residue-+ Thus the compound of benzylthiocarbimide with aldehyde-ammonia would be a benzylated derivative of Nencki's " DGthytiden-t hio hams tofa mrnoniak.'' The first question now was-can homologues of methyl be substi-tuted for the methyl-groups ? The answer was obtained as follows :-1 mol. benzylthiocarbimide dissolved in spirit was added to a spirituous solution containing 2 mols. of ordinary (hydrated) iso-valeraldehydc-ammonia. Crystals soon began to separate and the mixture was exposed freely to the air (at ordinary temperature) till most of the liquid had evaporated. The crystalline mass was drained, and pressed on the filter-pump washed lightly with spirit and dissolved in hot absolute alcohol. The latter somewhat decomposed the substance,-valeraldehyde and ammonia being evolved,-but on cooling beautiful snow-white silky needles separated forming a felted mass which retained much mother-liquor.It was thrown on the filter-pump washed repeatedly with cold alcohol and dried over sulphuric acid in a vacuum. The substance is insoluble in water soluble easily in hot sparingly in cold alcohol soluble in chloroform ether and bisulphide of carbon, and easily soluble in warm benzene. It melts at 161-162" with decomposition. Silver nitrate gives a finely granular white pre-cipitate which blackens gradually on standing or instantly on addition of ammonia. The alcoholic solution is slowly desulphurised by boiling with alkaline lead solution. The following data were obtained on analysis :-0.2313 gram burnt with lead chromate gave 0.5764 CO and 0.1932 &O, or C = 67-96 per cent. ; H = 9.28 per cent. or C = 67.92 per cent. ; H = 9.20 per cent. 0.2264 gram gave 0.5639 CO and 0.1875 HzO 414 DIXON THE ACTION OF ISOTHIOCYANATES 0.2564 gram burnt with copper oxide gave 29 C.C.N at 9" C. and 755 mm., or 13.50 per cent. N. 0.3042 gram evaporated to dryness with sodium hydrate in a nickel crucible and fused with potassium nitrat,e,* gave 0.2170 BaS04, or S = 9.80 per cent., which agreev wit'h the formula CIeH,,N3S. 67-65 9.10 C18 215.46 . H, 29-00 . N3 42.03 . S 31-98 . 318.47 S'i.96 6'7.92 - I 9.28 9.20 - -Experiment. Theory. I 1 11. 1 111. 1 IT. 13.19 -10.04 1 -- 13.50 -- - 9 *80 -____-____-- I - 1 - 1 - 1 -The reaction may be represented thus :-C,H,*NCS + 2CH(CH,),*CH,*COH,NH3 = C,H,gN,S + 2H20, and the provisional formula ascribed is-This compound is accordingly homologous with that previously described butyl-groups being substituted for the metlhyl-groups.The next question was Can other radicles be substituted for the benzyl-group ? To this an affirmative answer was also obt,ained. (a.) Ethylthiocarbinzide and A1dehyde-arnmonia.f-Warm concentrated alcoholic s o h tions of ethylthiocarbimide (L mol.) and aldehyde-ammonia (2 mols.) were mixed. On cooling, crystals separated which were collected and pressed. After two recrystallisations from spirit they were found to melt-though not without decomposition-at 135-136". At a few degrees higher they decompose completely with evolution of gas. * This is the method now regularly used by Professor Reynolds for the determi-nation of sulphur (and halogens) in suitable thio-compounds ; it gives very satisfac-tory results.j- By the action of aldehyde-ammonia on ethylthiocarbimide R. Schiff obtained results which will be referred to later on. The details will probably be published shortly ON THE ALDEHYDE-AMMONIAS. 415 C 83 5'9 . H, 15-00 . . . . . . . . . . . . . . . . . N 42.03 . S 31-98 . . . . . . . . . . . . . . . . . 172 -80 Analytical data :-0.2419 gram burnt with lead chromate gave 0.4315 CO and 0.1911 HZO, or C = 48.64; H = 8.77. 0.2534 gram burnt with copper oxide gave 54.1 C.C. N at 10" C and $42 mm., or N = 24.94 per cent. 0.3394 gram evaporated to dryness with sodium hydrate solution and fused with nitre gave 0.4484 gram BaS04, or S = 18.16 per cent. This agrees with the formula C7HI5K3S. 48 -49 8-68 24.32 18.50 ---1 Theory.Experiment. 11. ' 111. I - I -The structural formula may be provisionally written-Allylthiocarbimide and Aldehyde-am;izonia.* The ally1 compound was prepared similarly to the preceding. It formed white woolly masses of needles which after two recrystal-lisations from spirit melted a t 108-109". Analytical data :-0,2057 gram burnt with lead chromate gave 0.3913 CO and 0.1621 HZO, or C = 51.87; H = 8.75. 0.2465 gram burnt with copper oxide gave 47.6 C.C. N at 12' C. and 767 mm., or N = 23.13 per cent. * See note under ethylthiocarbimide j ante 416 DIXON THE ACTION OF ISOTHIOCYANATES Theory. I____-51.83 8.11 22-75 17.30 0.1423 gram evaporatled to dryness with sodium hydrate solution, and fused with nitre gave 0.1820 BaS04 from which the formula C8Hl,N3S is deduced.or S = 17.58 per cent., I. 11. 111. 51 * 87 - -8 -75 - -- 23 '13 - ___-- 17 '58 --~ I I Experiment. C 95.76 . N3 42.03 . S 31.98 . HlS 15.00 . which may be represented-(C,H,)*cH<;% . S%H - C H < ~ ~ , ( b . ) Phenylthiocarbimide and Aldehyde-anarnonia.* Warm concentrated alcoholic solutions of 1 mol. thiocarbimide and 2 mols. aldehyde ammonia were mixed. The mixture " set " instantly to a yellowish-white paste. This was freed from the mother-liquor, which it obstinately retains by squeezing in a cloth. The mass was recrystallised three times from warm alcohol and the product dried over sulphuric acid in a vacuum. The pure substance thus obtained crystallises in fine silyer-white needles which melt at 148-149" with browning and copious evolution of gas.The substance is insoluble in water but decomposed by boiling with it ; sduble in alcohol ether and chloroform. The alcoholic solution is freely desulphurised by warming with alkaline lead solution. Silver nitrate in excess gives a white precipitate which rapidly blackens, even in a freezing mixture. Results of analysis :-0.2020 gram burnt with lead chromate gave 0.4405 GO2 and 0.1331 HtO, or C = 59.46 per cent. ; H = 7.32 per cent. or C == 59.43 per cent.; H = 7.43 per cent. 0.2188 gram gave 0.4769 CO and 0.1465 H20, 0.2070 gram burnt with copper oxide gave 32.6 C.C. X at 9" C. and 777 mm., or N = 19.36 per cent. * See note under ethyl thiocarbiniide ante ON THE ALDEHYDE-AMMONIhS.417 11. I 111. ____--59-43 -7'43 -- 19-36 - -0.4600 gram evaporated to dryness with sodium hydrate solution and fused with nitre; gave 0.4943 gram BaS04, or S = 14.77 per cent., from which the formula C,,H,,N,S is deduced. IV. ---14 -77 Theory. C, 131 -67 . H15 15'00. N 42.03. S 31.98 . 59 -66 6-79 19.04 14.49 The structural formula (provisional) is-A homologue of the latter was next obtained. ( c . ) Phenylthiocarbimide and Valeraldehyde-ammonia. Alcoholic solutions were mixed ; on warming a precipitate separated which was drained and pressed. The mass was twice recrystallised from alcohol Fine snowy-white needles were thus obtained which when dried over sulphuric acid in a vacuum melt with decomposition at 152-153".The dry substance becomes SO electrical on slight friction that the particles fly about. The following data were obtained :-0.2057 gram burnt with lead chromate gave 0.5036 CO and 0.1780 &O, or C = 66.76 per cent.; H = 9.61 per cent. 0.2043 gram burnt with copper oxide gave 23.4 C.C. N at 7" C. and 77 mm., or N = 14-07 per cent. 0.2988 gram treated with sodium hydrate and nitre (see above) gave 0.2330 BaSOj, or S = 10.72 per cent., which agrees with the formula C17H27N3S 418 DIXON THE ACTION OF ISOTHIOCYANATES C, 2G3-49 . S 31.98 . H,; 27.00 . N 42'03 . Experiment. Theory. ' 66 -83 66 -76 A 13 -80 14 -07 10 -50 8 -86 9.61 The structural formula may be written-N(C6Hs)4H<$Eg s c < ~ ~ - ~ ~ < c 1 9 (d.) Orthotoly 1 t hiocarbimide and Aldehyde- ammonia.These substances unite at once when waym alcoholic solutions are mixed the contents of the vessel " setting '' to a snow-white mass. The yield is large-over 90 per cent. of the theoretical but as this substance like all the preceding is decomposed by hot alcohol the final yield of pure substance is small. The crude compound was recrystallised three times from warm alcohol thus were obtained short white prisms insoluble in water and melting a t 158-159" w i t h decomposition and evolution of gas. The substance dried over sulphuric acid in a vacuum gave the following results on analysis :-0.2264 gram burnt with lead chromate gave 0.507'5 CO and 0.1548 H20, or C = 61.13; H = 7.59. 0.2930 gram burnt with copper oxide gave 45.1 C.C.N at 10" C. and o r N = 18-30 per cent. 0.3250 gram treated with sodium hydrate and nitre gave 0.3236 755 mm., Bas04 or S = 13.68 per cent., from which the formula C12HI,,N3S is deduced ON THE ALDEHYDE-AMMONIAS. 419 ----143 '64 . Hi 17-00 . 42-03 . 2 31.98 . Theory. 61.21 7 '24 17'91 13-62 Experiment. I. 61-13 7 -59 - -11. 111. ----- --18 '30 - - 13.68 The reaction may be formulated as in the case of the isomeric benzyl compound and the structure represented thus :-Reference bas been made in the early part of this paper to the fact that R. Schiff (Bey. 9 565) has also obtained compounds by the union of aldehyde-ammonia with certain " mustard oils." As his method of operating was essentially the same as that which I have described above whilst on the other hand the resulting compounds were quite different I must indicate briefly the nature of his result,s.(I.) CGHBeNCS + CJ€,O,NH,. By the action of these substances upon one another in alcoholic solution Schiff obtained a compound to which he assigns the formula C,,H,,N,O,S,. The structure he considers may be expressed by the following formula which though not proved " accords perfectly with the mode of formation and reactions." I NH The melting point of this substance is given at 148" ; the compound which I obtained from the same materials melts at 148-149' 420 DIXON THE ACTION OF ISOTHIOCYANATES c H . . . . . N . 8 . O . For the purpose of comparison I here tabulate the analytical results obtained by Schiff and by myself together with the values calculated for the respective formulae C22H3JY502Sz and C11H15N3S.57.22 5'7'53 6-73 7-05 15.21 15'30 13-89 14.42 6.95 -C22H31N502S2 (Schiff) . Experiment. 57.26 6-95 ---I Theory* I-, C H . N . . s 59-66 6-79 19-04 14-49 59-46 7-32 19-36 14-77 ~ CIIH,,N,S (Dixon). i Experiment. Theory. ~ I I. (11.) C3H6*NCS + C2H40,NH3. The compound obtained by the union of these compounds is described as having a similar constitution t'o the preceding. Em-pirical formula C,H3,N5S20 ; m. p. 107-108". The compound similarly obtained by mysslf has the empirical formula C,H,,N,S ; I append as before a table of analytical results with corresponding m. p. 108-109".calculated values. ~ --c . H . N . 8 . 0 . C,H,,N3S (Dixon). I C16H3,N5S202 (Schiff). 49'30 51-82 51 '8'7 7 -98 18 -03 16 *46 17 '58 - I 8.23 1 (111.) CZH5*NCS + CZH,O,NH,. The compound of ethylthiocarbimide with aldehyde-ammonia obtained similarly to the two preceding compounds is described as having an analogous composition and to it a similar structure is assigned. The melting point is given as 118-119". Empirical formula C14H3,N5S202. The compound obtained by me correspond ON THE ALDEHYDE-AMRIONIAS. 421 ~ with the description ‘‘white silvery needles” given by Schiff to the ethyl-compound; but its melting point is as already stated, 135-136” and its empirical formula C7H15N3S. As before I give a table of comparative data. C7HljN3S (Dixon).c . H . N . . . s . 0 . Theory. Experiment. I- I -c H . N S 4 - 4 9 48.64 8.68 8 -77 24-32 24 -94 18.50 18.16 45 -97 8 -50 19 * 21 17 *54 8 -78 I Theory. I Experiment. 46 -30 8 -50 - --As I have directly determined all the constituent’s of each of the substances I obtained and the analyses add up fairly satisfactorily i t is obviously impossible to admit that my compounds contain oxygen ; yet their characters agree in the main with those described by Schiff. In his paper he states that experiments directed with a view to determine whether hydroxyl-groups (whose existence he assumes) were present led to no result. I f the substances I obtained are really identical with Schiff’s compounds I can only conclude that he did not obtain them in a sufficiently pure state for analysis. The structural formulae given by myself are only provisional but I hope shortly to be in a position to make a further communication in which the constitution of these cornpounds shall be dealt with. Chemical Laboratory, University of Dddin, March lst 1888