THE ACTION O F AMINES ON SEMICARBAZONES. PART 11. 103 XVII1.-The Action of Amines on Semicarbaxones. Part I I . By FQRSYTH Jilni~s WrLsoN and ARCHIBALD BARCLAY CRAWFORD. Ie continuation of previous work (J. 1922 121 866) we have found that 1-menthylamine reacts normally with acetonesemicarbazone to give active acelor,e-6-)~e?zthylse~~car~a~o~2e CMe,:N*NH*CO*NH + C‘,,H,g*NIP2 = NH + C11,7e,:N*NH*C0.PU’H.C1,H1g from which 6-menthyZse?.iicurba,~ide7 N~2*NH*CO*NI-I*C,o~Ilg and its hydro-chloride have been obtained. These compounds including the beiizaldehyde derivative are laevorotatory in alcoholic solution. The action of esters of amino-acids on semicarbazones was next investigated. Ethyl m-aminobenzoate and acetonesemicarbazone re-acted normally on heating C~e,:PU’*NH*CO*nTH2+NH,=C6H,*CO,E t = CMe2:N*NH*C0.NH.CGH,.C0,Et + NH, giving acetone- 6- 3 - c a d -etho~~phenylsemicarbcczorze in good yield from which 6-3-carbethoxy-phe?zylsemicarbax ide NH,*KH*C O*NH*C 6H4*C O,Et and its hydro-chloride were obtained.Ethyl paminobenzoate also reacted normally with benzophenone- and acetone-semicarbazone (in the latter case with poor yield) giving the ketonic 6-4-carbetholry-phenylsemicarbaxones CR,:nT*NH*CO*NH*C6H4*Co,Et both of which underwent complete decomposition when hydrolysis was attempted. In view of what follows care was taken in all these cases to use dry materials and dry solvents so as to avoid any risk of hydrolysis. The ester, on heating with benzophenonesemicarbazone (molecular quantities), gave 3-diphe~aylnzethylelzeaminotetr~hydro~~~ina~oli~e-2 4-dioize (I), Methyl o-aminobenzoate reacted somewhat differently.this on hydroIysis with acid giving benzophenone and 3-amino -tetrahydroyuinazoline-2 4-dione (11) C6H4~c0-~.NH2 YH*CO de-scribed by Kunckell (Ber. 1910 43 1021). In addition methyl alcohol benzophenonecarbohydrazone (111) tetrahydroquinazoline-2 4-dione (IV) and small quantities of diphenyl ketazine and hydrazodicarbonamide were produced. Borsche and Merkwitz have shown (Ber. 1904 37 3177) that benzophenonesemicarbazone on heating gives (111) presumably by interaction with the hydrazone CPh,:N*NH*CO*NH +-NH,-N:CPh = NH + CO(NH*N:CPh,) (111) the hydrazone appar 104 WILSON AND CRAWFORD : ently resulting from the semicarbazone by loss of cyanic acid, CPh,:N*NH*CO*NH = CPh,*N*NH + HNCO.I n the present in-stance the formation of (111) and (IV) the latter investigated, among others by Griess (Ber. 1869 2 416) can be explained as resulting from the ester and the semicarbazone, which then gives (111) and (IV) the diphenyl ketazine and the hydrazodicarbonamide being produced by the decomposition of the semicarbazone as shown by Borsche and Merkwitz, gCPh,:N*NH*CO*NH = CPh,:N*N:CPh +NH,*CO*NH*NH*CO*NH2. The interaction of acetonesemicarbazone with methyl o-amino-benzoate proceeded quite abnormally as before molecular quan-tities were employed and care was taken t o use dry solvents. The acetone derivative (V) expected from the scheme CMe,:N-NH*CO*NH, was not produced; the products were ammonia methyl alcohol, 3-aminotetrahydroquinazoline-2 4-dione (11) (the chief solid pro-duct amounting to about half of the semicarbazone used) a con-siderable amount of dimethyl ketazine small quantities of tetra-hydroquinazoline-2 4-dione (IV) and of a substance m.p. 420", which could not be identified; it is noteworthy that no hydrazo-dicarbonamide was formed. It may be assumed that (V) 3-iso~o(pylideneam~~otetra~ydro~u~nazolin~e-2 4-dione (prepared by another method and described below) is fkst produced with formation of ammonia and methyl alcohol and that it may react further in one of two ways. It may decompose 2s A different explanation is necessary in this case. follows , A substance of the composition represented by (VI) was not obtained (the unidentified substance of m.p. 420" giving quite different analytical results) ; moreover it was found as mentioned later that (V) did not behave in this way on heating. The other possibility and the one which we regard as the probable explan-ation is that (V) reacts with acetonesemicarbazone to give dimethyl ketazine and the intermediate carbamino-derivative (VII) THE ACTION OF AMMES ON SEMICARBAZONES. PART 11. 105 C H <NHo?o + NH,*CO*NH*N:CMe = CiUe,:N*N:CMe + CQ -N*NH*CO*NH,, which then by loss of cyanic acid gives (11). Borsche and Merkwitz (Zoc. cit.) apparently assume loss of cyanic acid in a similar case. Auwers and others (Annden 1924 435, 277) have shown that tetrahydroindazole-2-carbonamide loses cyanic acid (identified as cyanuric acid) on heating a t 160°, CO-N*N:CMe, C6H4<NH'Y 0 (VSI.) C,H4<gH>NCO*NH -+ C6H,KN_>NH.A H Similarly Posner (Ber., RC :CH* R 1901,34,3976) found that compounds of the type m2,co.+ (R = akyl) obtained from semicarbazide and diketones give with silver nitrate the derivative R?:CH*!?R when R = Ph, A€"N the carbamino-compound is not formed on heating the reactants, the product being 3 5-diphenylpyrazole. The substance (IV) probably results together with (11) by interaction of (VII) with the ester : To test. these explanations (V) was prepared by boiling ordinary undried acetone with (11); curiously enough dried acetone did not react even on prolonged boiling 8 p-dichloropropane also proved unreactive. This substance (V) was easily hydrolysed into the parent compounds by water and by hot solvents containing water.It was scarcely affected by heating even at 220" for 2& hours it charred slightly and there was a slight odoixr of dimethyl ketazine, but most of the substance was recovered unchanged. Molecular quantities of (V) and acetonesemicarbazone on heating gave dimethyl ketazine and (11) this being in accordance with the explanation advanced by us. This work will be continued. E x F E R I 3lr E N T A L. 3-Bent7qlamine and Acetonesemicurbaxone.-The 1-menthylamine, prepased by the method of Beckmann (Annalen 1889 250 325) and of Wallach (ibid. 1893 276 327) wa8 distilled directly in a current of hydrogen into a polarimeter tube ; it gave [m] - 39-41' E 106 WILSON AND CRAWFORD : [Wallach records - 38.07"; Tutin and Kipping (J.1904 85 69) record - 39-92']. Equimolecular quantities previously heated to 165" were mixed and kept at this temperature for 15 minutes when solution with copious evolution of ammonia took place. The cooled melt dis-solved in a little alcohol was poured into dilute acetic acid the solid which separated dissolved completely in hot alcohol from which on cooling active acetone-8-menthylsemicarbazone was de-posited in clusters of small colourless needles m. p. 128" (Found : N = 16.62 16.73. C,,H2,0N requires N = 16.60 yo). 0.5024 Gram in 25 C.C. of absolute alcohol gave ar - 2.612" ( I = Z), whence [a]:" - 64.93". The substance was soluble in the usual organic solvents. Active 6-Menthylsemicarbaxide.-The semicarbazone was heated at 70" with Ilr-hydrochloric acid (5 parts) until completely dis-solved ; the residue obtained by evaporation under reduced pressure was recrystallised from alcohol which gave s-menthylsemicccrbazide hydrochloride as a gelatinous mass; after suction and washing with ether it assumed a fibrous apparently non-crystalline appearance and melted a t 203-204" (Found C1=14-02,14*22.C,,H,,ON,,HCl requires C1 = 14.22%). 0.5024 Gram in 25 C.C. of absolute alcohol gave a%' - 2.62" ( I = Z) whence [a]$" - 65-18". It was soluble in alcohol or hot water insoluble in ether or benzene and could not be obtained in a definitely crysta.lline form. 6-Menthylsemi-carbuzide obtained by dissolving the hydrochloride in hot dilute alcohol adding sodium hydroxide solution in slight excess and then immediately diluting and cooling in ice crystallised from light petroleum containing a little benzene in microscopic prisms, m.p. 138" (Found N = 19.89 19.83. CllH23ON3 requires N = 19.71%). 0-4994 Gram in 25 C.C. of absolute alcohol gave a$' -3.11" (1 = 2) whence [a]2Do' - 77.94". It was soluble in the usual organic solvents on heating solutions cannot be kept as they become green after one day. Addition of ethereal hydrogen chloride in slight excess to an absolute alcoholic solution precipitated the gelatinous hydrochloride. The benxylidene derivative obtained by shaking an alcoholic solution of the hydrochloride with a little benzaldehyde and then adding a little water solidified on standing and crystallised from alcohol in which it was very soluble in fine, rhombic prisms m.p. 111" (Found N = 13.96. C,,H,,0N3 requires N = 13.95%). 1.898 Grams in 100 C.C. of absolute alcohol gave ago - 1.79" (1 = 2) whence [a]?' - 47.18'. Solutions be-came green on standing. Ethyl m-Aminobenxmte and Acetonesemicarbaxone.-The two substances (1-6 mols. of the latter) were heated a t 165" until the Yield 65 yo THE ACTION OF AMINES ON SEiMICARBSZONES. PART 11. 107 evolution of ammonia began to slacken (20 minutes). The cooled melt was gently heated with a little alcohol which after filtration horn hydrazodicarbonamide deposited a solid on cooling ; this was mashed with a little alcohol and recrystallised from this solvent. A little more hydrazodicarbonamide was deposited followed by cal ourless plates of acetone- 6-3 -carbethosyphen ylserPzicarbazon e m.p. 146" (Found N = 1594 16.02. C13H1,03W3 requires N = 15.97y0). It was moderately soluble in alcohol very soluble in pyridine sparingly soluble or insoluble in other bolveiits. Yield S O X . Hydrolysis was effected by covering the substance with 3iN-hydrochloric acid and warming to 70"; the solid which scparated on cooling in ice gave after recrystallisation from alcohol, prisms of 6-3-carbetho~yphe3lylsemicnrbazicle hydrochloride m. p. 172" (Found C1 = 13.56 13-72. Cl0Hl3O3N3,HC1 requires C1 = 13-68:/,); it was readily soluble in hot (not very soluble in cold) water and hot alcohol and reduced Fehling's solution and am-nioniacal silver nitrate. 6- 3 - Carb et hoxyphenzylsemicarbaxide pre-pared in the usual manner from this salt with sodium hydroxide, separated from benzene in small prisms m.p. 119" ; it was Tery soluble in alcohol chloroform or hot benzene and sparingly soluble in water (Found N = 18-87 18-88. C,,-$,303N3 requires N = 15-83y0). The beizxylideize derivative prepared from a hot aqueous solution of the hydrochloride and benzaldehyde separated from alcohol in fine hair-like needles m. p. 144" very soluble in most solvents except water (Found N = 13-62 13-50. C1,H1,03N, requires N = 13.50:/0). Ethyl p-Arninobenzoate and BenxopheizonesernicarbaxolzP,.-The semicarbazone was added during 1 hour to the ester (2 mols.) heated at 230"; a gentle evolution of ammonia took place and the heat'ing was continued for 15 minutes after the last addition. The alcoholic extract of the cooled melt after filtering from hydrazo-dicarbonamide was poured into dilute acetic acid to remove excess of ester.The solid which separated on standing was extracted with cold toluene ; the insoluble portion on recrystallisation from benzene gave pearly plates of benxophenone-6-4-carbethoxyph.,nyl-semicarbazone m. p. 168" (Found N = 11.03 10.68. C,3H,10,Pa'3 requires N = 10.85%). The toluene extract contained diphenyl ketazine and benzophenonecarbohydrazone. The substance was soluble in most organic solvents but almost insoluble in cold benzene, toluene or light petroleum ; exposure to light converted it withoilt change of melting point into a lemon-yellow modification which gave colourless solutions. Ethyl p-Aminobenxoate and Acetonesemicarbazone.-The semi-carbazone was added during 20 minutes to the ester (1 mol.of Yield about 57%. E* 108 WILSON AND CRAWFORD: each) heated a t 190-200'. The alcoholic extract of the cooled melt atered from a small amount of hydrazodicarbonamide was evaporated and the residue recrystallised from alcohol. The crystals obtained were washed with cold acetone to dissolve a small quantity of a substance which was not identified (prisms from acetone m. p. 130" ; found N = 14.2%) ; several recrystallisations from alcohol gave hexagonal tablets of metone-6-4-carhethoxyphenyl-semicarbaxone m. p. 194'. There was some difficulty in separating it from a very small amount of a powdery substance m. p. 210°, which had almost the same solubility. The estimation of nitrogen in the semicarbazone offered considerable difficulty the results being high and not concordant due possibly to the production of methane (compare Haas J.1906 59 570; Dunstan and Carr, P. 1896 12 48) a 2-metre tube charged with lead chromate gave satisfactory results (Found N = 16.18 16.22. C,,H,,O,N, requires N = 15@7y0). The substance was soluble in alcohol or hot benzene slightly soluble in hot acetone insoluble in other solvents. Yield about 13%. Methyl o-Aminobenzmte and Benzophenonesemicarbazone.-Mole-cular quantities were heated a t 210" for 40 minutes; ammonia was evoked and methyl alcohol distilled over. The melt on extrac-tion with boiling benzene gave a residue which was shown by treatment with hot pyridine to consist of a little hydrazodicarbon-a'mide and tetrahydroquinazoline-2 3-dione.Concentration of the benzene extract gave a mixture from which 3-diphenylmethylene-aminotetrahydroquinazoline-2 4-dione was isolated by fractionally precipitating a chloroform solution with light petroleum. Con-centration of these mother-liquors gave benzophenonecarbohydr-azone. Further concentration of the benzene extract yielded a little diphenyl ketazine. 3-Diphe~ylmethyleneaminote~rahydroquina~oline-2 4-dione crystal-lised from alcohol in large prisms m. p. 240" and was moderately soluble in hot chloroform or hot pyridine insoluble in ether (Found : N = 12-32 12.54. C21H1502N3 requires N = 12-31y0). Boiling for & hour with 2&V-hydrochloric acid effected hydrolysis into benzophenone and 3-aminotetrahydroquinazoline-2 4-dione.Kunckell obtained the hydrochloride from the base and alcoholic hydrogen chloride ; evidently aqueous acid did not produce this salt. I f the reaction product is worked up in the usual way with acetic acid the 3-amino-compound is obtained and not the benzophenone derivative. Methyl o-Aminobenzoate and Acetonesemicarbaxone.-Equimole-cular quantities heated a t 195" for 3 0 4 0 minutes gave ammonia and a distillate containing methyl alcohol and dimethyl ketazine THE ACTION OF AMMES ON SEMICARBAZONES. PART 11. 109 water acetone or hydrazine was not present. A white sublimate, very small in amount and probably ammonium carbamate gradually formed and the melt ultimately solidified; it was then extracted with a little boiling benzene to remove resinous matter and un-changed ester.The residue was washed with light petroleum and fractionally recrystallised from pyridine which dissolved it com-pletely indicating absence of hydrazodicarbonamide. The f i s t crop of crystals coiisisted of 3-aminotetrahydroquiazoline-8 4-dione concentration yielded large regular efflorescent prisms, almost complete evaporation gave tetrathydroquinazoline-2 4-dione. The prisms after recrystallisation from pyridine charred at 390" on slow heating but melted at 420" in a previously heated bath (sodium-potassium nitrates). This substance which could not be identified contained about 38 % of pyridine of crystallisation which was expelled a t 105" ; analysis then gave C = 60.32 ; H = 4-00 ; N = 17-41; 0 (by diff.) = 18-27. The amount of this compound was relatively small; it was insoluble in the usual solvents includ-ing hydrochloric acid soluble in pyridine or sodium hydroxide.The solution in conccntrated sulphuric acid became pink on standing. obtained by boiling the 3-amino-compound with ordinary undried acetone until completely dissolved (5 hours) crystallised from dry acetone in prisms m. p. 212" (Found N = 19-55 19.58. C,,H1,0,N3 requires N = 19.35:/,). It was soluble in the usual organic solvents except ether and light petroleum; crystals from benzene were efnorescent containing apparently solvent of crystallisation. A mixture of this substaiice with acetonesemicarbazone on heating at 190" for 35 minutes melted at f i s t and then gradually solidified, ammonia was evolved and dimethyl ketazine distilled in quantity.The solid after removal of tarry matter by washing with ether and benzene was identified as 3-aminotetrahydroquinazoline-2 4-dione the evolution of ammonia was probably due to a decomposition of the semicarbazone which gives this gas on heating. The various substances mentioned were fully characterised as such by their properties and if necessary by analysis and pre-paration of derivatives. 3 -isoE'ropgl ideiz earninotetrahydroguiw azoline- 2 4-dio jie, In conclusion we wish to thank the Carnegie Trust for the Universities of Scotland for a grant which has partly defrayed the expenses of this work. THE ROSAL TECHNICAL COLLEGE, GLASGOW. [Eeceiced October 7th 1924. THE ACTION O F AMINES ON SEMICARBAZONES. PART 11.103 XVII1.-The Action of Amines on Semicarbaxones. Part I I . By FQRSYTH Jilni~s WrLsoN and ARCHIBALD BARCLAY CRAWFORD. Ie continuation of previous work (J. 1922 121 866) we have found that 1-menthylamine reacts normally with acetonesemicarbazone to give active acelor,e-6-)~e?zthylse~~car~a~o~2e CMe,:N*NH*CO*NH + C‘,,H,g*NIP2 = NH + C11,7e,:N*NH*C0.PU’H.C1,H1g from which 6-menthyZse?.iicurba,~ide7 N~2*NH*CO*NI-I*C,o~Ilg and its hydro-chloride have been obtained. These compounds including the beiizaldehyde derivative are laevorotatory in alcoholic solution. The action of esters of amino-acids on semicarbazones was next investigated. Ethyl m-aminobenzoate and acetonesemicarbazone re-acted normally on heating C~e,:PU’*NH*CO*nTH2+NH,=C6H,*CO,E t = CMe2:N*NH*C0.NH.CGH,.C0,Et + NH, giving acetone- 6- 3 - c a d -etho~~phenylsemicarbcczorze in good yield from which 6-3-carbethoxy-phe?zylsemicarbax ide NH,*KH*C O*NH*C 6H4*C O,Et and its hydro-chloride were obtained.Ethyl paminobenzoate also reacted normally with benzophenone- and acetone-semicarbazone (in the latter case with poor yield) giving the ketonic 6-4-carbetholry-phenylsemicarbaxones CR,:nT*NH*CO*NH*C6H4*Co,Et both of which underwent complete decomposition when hydrolysis was attempted. In view of what follows care was taken in all these cases to use dry materials and dry solvents so as to avoid any risk of hydrolysis. The ester, on heating with benzophenonesemicarbazone (molecular quantities), gave 3-diphe~aylnzethylelzeaminotetr~hydro~~~ina~oli~e-2 4-dioize (I), Methyl o-aminobenzoate reacted somewhat differently.this on hydroIysis with acid giving benzophenone and 3-amino -tetrahydroyuinazoline-2 4-dione (11) C6H4~c0-~.NH2 YH*CO de-scribed by Kunckell (Ber. 1910 43 1021). In addition methyl alcohol benzophenonecarbohydrazone (111) tetrahydroquinazoline-2 4-dione (IV) and small quantities of diphenyl ketazine and hydrazodicarbonamide were produced. Borsche and Merkwitz have shown (Ber. 1904 37 3177) that benzophenonesemicarbazone on heating gives (111) presumably by interaction with the hydrazone CPh,:N*NH*CO*NH +-NH,-N:CPh = NH + CO(NH*N:CPh,) (111) the hydrazone appar 104 WILSON AND CRAWFORD : ently resulting from the semicarbazone by loss of cyanic acid, CPh,:N*NH*CO*NH = CPh,*N*NH + HNCO. I n the present in-stance the formation of (111) and (IV) the latter investigated, among others by Griess (Ber.1869 2 416) can be explained as resulting from the ester and the semicarbazone, which then gives (111) and (IV) the diphenyl ketazine and the hydrazodicarbonamide being produced by the decomposition of the semicarbazone as shown by Borsche and Merkwitz, gCPh,:N*NH*CO*NH = CPh,:N*N:CPh +NH,*CO*NH*NH*CO*NH2. The interaction of acetonesemicarbazone with methyl o-amino-benzoate proceeded quite abnormally as before molecular quan-tities were employed and care was taken t o use dry solvents. The acetone derivative (V) expected from the scheme CMe,:N-NH*CO*NH, was not produced; the products were ammonia methyl alcohol, 3-aminotetrahydroquinazoline-2 4-dione (11) (the chief solid pro-duct amounting to about half of the semicarbazone used) a con-siderable amount of dimethyl ketazine small quantities of tetra-hydroquinazoline-2 4-dione (IV) and of a substance m.p. 420", which could not be identified; it is noteworthy that no hydrazo-dicarbonamide was formed. It may be assumed that (V) 3-iso~o(pylideneam~~otetra~ydro~u~nazolin~e-2 4-dione (prepared by another method and described below) is fkst produced with formation of ammonia and methyl alcohol and that it may react further in one of two ways. It may decompose 2s A different explanation is necessary in this case. follows , A substance of the composition represented by (VI) was not obtained (the unidentified substance of m. p. 420" giving quite different analytical results) ; moreover it was found as mentioned later that (V) did not behave in this way on heating.The other possibility and the one which we regard as the probable explan-ation is that (V) reacts with acetonesemicarbazone to give dimethyl ketazine and the intermediate carbamino-derivative (VII) THE ACTION OF AMMES ON SEMICARBAZONES. PART 11. 105 C H <NHo?o + NH,*CO*NH*N:CMe = CiUe,:N*N:CMe + CQ -N*NH*CO*NH,, which then by loss of cyanic acid gives (11). Borsche and Merkwitz (Zoc. cit.) apparently assume loss of cyanic acid in a similar case. Auwers and others (Annden 1924 435, 277) have shown that tetrahydroindazole-2-carbonamide loses cyanic acid (identified as cyanuric acid) on heating a t 160°, CO-N*N:CMe, C6H4<NH'Y 0 (VSI.) C,H4<gH>NCO*NH -+ C6H,KN_>NH.A H Similarly Posner (Ber., RC :CH* R 1901,34,3976) found that compounds of the type m2,co.+ (R = akyl) obtained from semicarbazide and diketones give with silver nitrate the derivative R?:CH*!?R when R = Ph, A€"N the carbamino-compound is not formed on heating the reactants, the product being 3 5-diphenylpyrazole. The substance (IV) probably results together with (11) by interaction of (VII) with the ester : To test. these explanations (V) was prepared by boiling ordinary undried acetone with (11); curiously enough dried acetone did not react even on prolonged boiling 8 p-dichloropropane also proved unreactive. This substance (V) was easily hydrolysed into the parent compounds by water and by hot solvents containing water.It was scarcely affected by heating even at 220" for 2& hours it charred slightly and there was a slight odoixr of dimethyl ketazine, but most of the substance was recovered unchanged. Molecular quantities of (V) and acetonesemicarbazone on heating gave dimethyl ketazine and (11) this being in accordance with the explanation advanced by us. This work will be continued. E x F E R I 3lr E N T A L. 3-Bent7qlamine and Acetonesemicurbaxone.-The 1-menthylamine, prepased by the method of Beckmann (Annalen 1889 250 325) and of Wallach (ibid. 1893 276 327) wa8 distilled directly in a current of hydrogen into a polarimeter tube ; it gave [m] - 39-41' E 106 WILSON AND CRAWFORD : [Wallach records - 38.07"; Tutin and Kipping (J. 1904 85 69) record - 39-92'].Equimolecular quantities previously heated to 165" were mixed and kept at this temperature for 15 minutes when solution with copious evolution of ammonia took place. The cooled melt dis-solved in a little alcohol was poured into dilute acetic acid the solid which separated dissolved completely in hot alcohol from which on cooling active acetone-8-menthylsemicarbazone was de-posited in clusters of small colourless needles m. p. 128" (Found : N = 16.62 16.73. C,,H2,0N requires N = 16.60 yo). 0.5024 Gram in 25 C.C. of absolute alcohol gave ar - 2.612" ( I = Z), whence [a]:" - 64.93". The substance was soluble in the usual organic solvents. Active 6-Menthylsemicarbaxide.-The semicarbazone was heated at 70" with Ilr-hydrochloric acid (5 parts) until completely dis-solved ; the residue obtained by evaporation under reduced pressure was recrystallised from alcohol which gave s-menthylsemicccrbazide hydrochloride as a gelatinous mass; after suction and washing with ether it assumed a fibrous apparently non-crystalline appearance and melted a t 203-204" (Found C1=14-02,14*22.C,,H,,ON,,HCl requires C1 = 14.22%). 0.5024 Gram in 25 C.C. of absolute alcohol gave a%' - 2.62" ( I = Z) whence [a]$" - 65-18". It was soluble in alcohol or hot water insoluble in ether or benzene and could not be obtained in a definitely crysta.lline form. 6-Menthylsemi-carbuzide obtained by dissolving the hydrochloride in hot dilute alcohol adding sodium hydroxide solution in slight excess and then immediately diluting and cooling in ice crystallised from light petroleum containing a little benzene in microscopic prisms, m.p. 138" (Found N = 19.89 19.83. CllH23ON3 requires N = 19.71%). 0-4994 Gram in 25 C.C. of absolute alcohol gave a$' -3.11" (1 = 2) whence [a]2Do' - 77.94". It was soluble in the usual organic solvents on heating solutions cannot be kept as they become green after one day. Addition of ethereal hydrogen chloride in slight excess to an absolute alcoholic solution precipitated the gelatinous hydrochloride. The benxylidene derivative obtained by shaking an alcoholic solution of the hydrochloride with a little benzaldehyde and then adding a little water solidified on standing and crystallised from alcohol in which it was very soluble in fine, rhombic prisms m. p. 111" (Found N = 13.96.C,,H,,0N3 requires N = 13.95%). 1.898 Grams in 100 C.C. of absolute alcohol gave ago - 1.79" (1 = 2) whence [a]?' - 47.18'. Solutions be-came green on standing. Ethyl m-Aminobenxmte and Acetonesemicarbaxone.-The two substances (1-6 mols. of the latter) were heated a t 165" until the Yield 65 yo THE ACTION OF AMINES ON SEiMICARBSZONES. PART 11. 107 evolution of ammonia began to slacken (20 minutes). The cooled melt was gently heated with a little alcohol which after filtration horn hydrazodicarbonamide deposited a solid on cooling ; this was mashed with a little alcohol and recrystallised from this solvent. A little more hydrazodicarbonamide was deposited followed by cal ourless plates of acetone- 6-3 -carbethosyphen ylserPzicarbazon e m. p. 146" (Found N = 1594 16.02.C13H1,03W3 requires N = 15.97y0). It was moderately soluble in alcohol very soluble in pyridine sparingly soluble or insoluble in other bolveiits. Yield S O X . Hydrolysis was effected by covering the substance with 3iN-hydrochloric acid and warming to 70"; the solid which scparated on cooling in ice gave after recrystallisation from alcohol, prisms of 6-3-carbetho~yphe3lylsemicnrbazicle hydrochloride m. p. 172" (Found C1 = 13.56 13-72. Cl0Hl3O3N3,HC1 requires C1 = 13-68:/,); it was readily soluble in hot (not very soluble in cold) water and hot alcohol and reduced Fehling's solution and am-nioniacal silver nitrate. 6- 3 - Carb et hoxyphenzylsemicarbaxide pre-pared in the usual manner from this salt with sodium hydroxide, separated from benzene in small prisms m.p. 119" ; it was Tery soluble in alcohol chloroform or hot benzene and sparingly soluble in water (Found N = 18-87 18-88. C,,-$,303N3 requires N = 15-83y0). The beizxylideize derivative prepared from a hot aqueous solution of the hydrochloride and benzaldehyde separated from alcohol in fine hair-like needles m. p. 144" very soluble in most solvents except water (Found N = 13-62 13-50. C1,H1,03N, requires N = 13.50:/0). Ethyl p-Arninobenzoate and BenxopheizonesernicarbaxolzP,.-The semicarbazone was added during 1 hour to the ester (2 mols.) heated at 230"; a gentle evolution of ammonia took place and the heat'ing was continued for 15 minutes after the last addition. The alcoholic extract of the cooled melt after filtering from hydrazo-dicarbonamide was poured into dilute acetic acid to remove excess of ester.The solid which separated on standing was extracted with cold toluene ; the insoluble portion on recrystallisation from benzene gave pearly plates of benxophenone-6-4-carbethoxyph.,nyl-semicarbazone m. p. 168" (Found N = 11.03 10.68. C,3H,10,Pa'3 requires N = 10.85%). The toluene extract contained diphenyl ketazine and benzophenonecarbohydrazone. The substance was soluble in most organic solvents but almost insoluble in cold benzene, toluene or light petroleum ; exposure to light converted it withoilt change of melting point into a lemon-yellow modification which gave colourless solutions. Ethyl p-Aminobenxoate and Acetonesemicarbazone.-The semi-carbazone was added during 20 minutes to the ester (1 mol.of Yield about 57%. E* 108 WILSON AND CRAWFORD: each) heated a t 190-200'. The alcoholic extract of the cooled melt atered from a small amount of hydrazodicarbonamide was evaporated and the residue recrystallised from alcohol. The crystals obtained were washed with cold acetone to dissolve a small quantity of a substance which was not identified (prisms from acetone m. p. 130" ; found N = 14.2%) ; several recrystallisations from alcohol gave hexagonal tablets of metone-6-4-carhethoxyphenyl-semicarbaxone m. p. 194'. There was some difficulty in separating it from a very small amount of a powdery substance m. p. 210°, which had almost the same solubility. The estimation of nitrogen in the semicarbazone offered considerable difficulty the results being high and not concordant due possibly to the production of methane (compare Haas J.1906 59 570; Dunstan and Carr, P. 1896 12 48) a 2-metre tube charged with lead chromate gave satisfactory results (Found N = 16.18 16.22. C,,H,,O,N, requires N = 15@7y0). The substance was soluble in alcohol or hot benzene slightly soluble in hot acetone insoluble in other solvents. Yield about 13%. Methyl o-Aminobenzmte and Benzophenonesemicarbazone.-Mole-cular quantities were heated a t 210" for 40 minutes; ammonia was evoked and methyl alcohol distilled over. The melt on extrac-tion with boiling benzene gave a residue which was shown by treatment with hot pyridine to consist of a little hydrazodicarbon-a'mide and tetrahydroquinazoline-2 3-dione.Concentration of the benzene extract gave a mixture from which 3-diphenylmethylene-aminotetrahydroquinazoline-2 4-dione was isolated by fractionally precipitating a chloroform solution with light petroleum. Con-centration of these mother-liquors gave benzophenonecarbohydr-azone. Further concentration of the benzene extract yielded a little diphenyl ketazine. 3-Diphe~ylmethyleneaminote~rahydroquina~oline-2 4-dione crystal-lised from alcohol in large prisms m. p. 240" and was moderately soluble in hot chloroform or hot pyridine insoluble in ether (Found : N = 12-32 12.54. C21H1502N3 requires N = 12-31y0). Boiling for & hour with 2&V-hydrochloric acid effected hydrolysis into benzophenone and 3-aminotetrahydroquinazoline-2 4-dione. Kunckell obtained the hydrochloride from the base and alcoholic hydrogen chloride ; evidently aqueous acid did not produce this salt.I f the reaction product is worked up in the usual way with acetic acid the 3-amino-compound is obtained and not the benzophenone derivative. Methyl o-Aminobenzoate and Acetonesemicarbaxone.-Equimole-cular quantities heated a t 195" for 3 0 4 0 minutes gave ammonia and a distillate containing methyl alcohol and dimethyl ketazine THE ACTION OF AMMES ON SEMICARBAZONES. PART 11. 109 water acetone or hydrazine was not present. A white sublimate, very small in amount and probably ammonium carbamate gradually formed and the melt ultimately solidified; it was then extracted with a little boiling benzene to remove resinous matter and un-changed ester.The residue was washed with light petroleum and fractionally recrystallised from pyridine which dissolved it com-pletely indicating absence of hydrazodicarbonamide. The f i s t crop of crystals coiisisted of 3-aminotetrahydroquiazoline-8 4-dione concentration yielded large regular efflorescent prisms, almost complete evaporation gave tetrathydroquinazoline-2 4-dione. The prisms after recrystallisation from pyridine charred at 390" on slow heating but melted at 420" in a previously heated bath (sodium-potassium nitrates). This substance which could not be identified contained about 38 % of pyridine of crystallisation which was expelled a t 105" ; analysis then gave C = 60.32 ; H = 4-00 ; N = 17-41; 0 (by diff.) = 18-27. The amount of this compound was relatively small; it was insoluble in the usual solvents includ-ing hydrochloric acid soluble in pyridine or sodium hydroxide.The solution in conccntrated sulphuric acid became pink on standing. obtained by boiling the 3-amino-compound with ordinary undried acetone until completely dissolved (5 hours) crystallised from dry acetone in prisms m. p. 212" (Found N = 19-55 19.58. C,,H1,0,N3 requires N = 19.35:/,). It was soluble in the usual organic solvents except ether and light petroleum; crystals from benzene were efnorescent containing apparently solvent of crystallisation. A mixture of this substaiice with acetonesemicarbazone on heating at 190" for 35 minutes melted at f i s t and then gradually solidified, ammonia was evolved and dimethyl ketazine distilled in quantity. The solid after removal of tarry matter by washing with ether and benzene was identified as 3-aminotetrahydroquinazoline-2 4-dione the evolution of ammonia was probably due to a decomposition of the semicarbazone which gives this gas on heating. The various substances mentioned were fully characterised as such by their properties and if necessary by analysis and pre-paration of derivatives. 3 -isoE'ropgl ideiz earninotetrahydroguiw azoline- 2 4-dio jie, In conclusion we wish to thank the Carnegie Trust for the Universities of Scotland for a grant which has partly defrayed the expenses of this work. THE ROSAL TECHNICAL COLLEGE, GLASGOW. [Eeceiced October 7th 1924.