TERTIARY ACIDIC, ETC., DERIVATIVES OF D-CAMPHORIMIDE. 2237CCXXX1V.-The Tertiary Acidic and Alkyl Deriu-atiz'es of d- Carnphorimide.By WILLIAM C'HARLES EVANS.ALTHOUGH it is generally recognised that phthalic acid and cam-phoric acid exhibit striking analogies in chemical behaviour, thesimilarities existing between the two acids have not previously beentraced in the reactions of their imides. At the suggestion ofProfessor W. J. Pope, I have therefore endeavoured to ascertainto what extent the reactions by means of which the imidogenhydrogen atom in pht.halimide can be replaced by halogen atomsand by alkyl groups are capable of effecting similar substitutions ind-camphorimide ; that a very deep-rooted analogy in chemicalbehaviour exists between the two acid imides will be evident fromthe description of the modes of preparation of the compoundsdescribed below.Preparation of d-Camphorimide.A comparison of the various methods which have been describedfor the preparation of d-camphorimide showed that a methodidentical in principle with that given by Bredt (Amden, 1903,528, 344) is the most convenient for use in the preparation of thi2238 EVANS: THE TERTIARY ACIDIC AND ALKYLsubstance.d-Camphoric acid is gently boiled in a retort providedwith a long and wide-necked retort heated in a metal-bath; at thesame time a brisk current of dry ammonia gas is passed throughthe boiling acid from a steel storage cylinder. After the evolutionof water vapour has completely ceased, the material is distilled,and, in order to ensure that-no camphoric anhydride has escaped.conversion, the distillate is once more distilled in a current ofammonia gas.The d-camphorimide thus obtained is practicallypure, and, after crystallisation from dilute alcohol, melts at 243O.d-Camphorb romoimide, C,H1,<CO>N co Br ,To a cold solution of 12.3 grams of d-camphorimide and 2.7 gramsof sodium hydroxide in 125 C.C. of water is gradually added a well-cooled solution of 11 grams of bromine in 250 C.C. of water; awhite, crystalline substance immediately separates, which, aftercollection and crystallisation from benzene, is obtained in minute,white crystals, melting at 154O. The compound thus obtaineddissolves readily in chloroform, acetone, ether, or ethyl acetate, andis less soluble in alcohol or benzene.It is decomposed by hydriodicacid in accordance witrh the equation :@,,H,,02:NBr + 2HI = C,,H,40,:NH + HBr + I,,and, in accordance with this reaction, its analysis was effected bydissolving a weighed quantity in chloroform, to which a littlepotassium iodide and acetic acid had been added, and titrating theliberated iodine with thiosulphate solution :0.1856 required 15.4 C.C. thiosulphate (1 C.C. = 0.022690.1822 gave 0.3086 CO, and 0.0930 H,O.G,,H,,O,NBr requires Br=30*77; C=40*16; H=5.39 per cent.The following determinations of rotatory power were made inSolvent. Wejght in 25 C.C. a,. [ale.Benzene ............... 0.4853 gram + 051" + 12-0"), ............... 0.5960 ), 0.587 11'2 * ,, ...............0.7707 ,, 0.81 12-0Chloroforni ......... 0 '4 16 1 , , 0.512 13'69 , 0.6843 ,, 0-785 13'0$ 9 0.7lGO ,, 1 *29 12.8The substance is not completely stable in moist air, and to thismust be attributed the slight variations in specific rotatory powerobvious above.Na.&3,0,,5H20). Br = 30.36.C = 40.20 ; H = 5'67.2.2-dcm. tubes at 18O :.................DERIVATIVES OF D-CAMPHORIMIDE. 2239co d-Camphoriodoimide, C, A,,<cO>NI.d-Camphorimide (5 grams, 1 mol.) and sodium hydroxide (1.3grams, 1 mol.) are dissolved in water (350 c.c.), and the resultingsolution added slowly and with vigorous stirring to a well-cooledsolution of iodine (3-5 grams, 1 mol.), sodium bromide (5 grams),and bromine (2.3 grams, 1 mol.) in water (50 c.c.).A greyish-blacksolid immediately separates, which, on stirring, becomes brown ;after collection, washing, and drying in a vacuum, the substanceis crystallised from hot benzene, from which it separates in minute,light yellow crystals, melting and decomposing at 207O. The iodn-derivative thus obtained is readily soluble in acetone, chloroform,or ether, but less soluble in alcohol or benzene. It reacts withhydriodic acid in accordance with the following equation :CloH,,02:NI + HI = C,,H,,02:NH + I,,and, in accordance therewith, the iodine was determined by dis-solving a weighed quantity in chloroform, adding potassium iodideand acetic acid, and titrating with thiosulphate :0.2458 required 17-25 C.C. thiosulphate (1 C.C. =0*022690.1632 gave 0.2330 CO, and 0.0717 H,O.The following determinations of rotatory power were made :N~S20.$H2O.I =40'76.C=38*94; H=4-88.CloH,,02NI requires I = 41.37 ; C = 39.09 ; H = 4.56 per cent.Solvell t , Weight in 25 C.C. QD. i.1 D. Chloroform ......... 0-3852 gram + 0.514" in 2.2-dcm. tube. + 15.2' v ,. ......... 0.5130 , , 0.690 ,, 2-2 ,,9 , ......... 0.6448 , , 0'406 ,, 1 ,,,> 0.7468 ,, 0.470 ,, 1 ,, .........Benzene ............. 0.4055 ,, 0.260 ,, 1 ,,,, ............... 0.4383 ,, 0'280 ,, 1 ,,The solutions in chloroform rapidly undergo decompositionbecome deep violet in colour.dCamphorme t hqlimide, CsH,,<cO>NMe. coThe method of preparation of this substance described15.315.715-716.016.0andbyHoogewerff and van Dorp (Rec.trav. chim., 1893, 12, 13) may beconveniently replaced by the following simpler one. Camphorimide(5 grams) is dissolved in a mixture of 1*125N-potassium hydroxide(27.2 c.c., 1 mol.) and methyl iodide (4 grams); potassium iodidecommences to separate in the cold, and the reaction is completed byheating for two hours on the water-bath. After separation of thepotassium iodide and evaporation of the alcohol, the residue isdissolved in benzene ; the benzene solution, an evaporation, yield2240 EVANS: THE TERTIARY ACIDIC AND ALKYLa crystalline residue of d-camphormethylimide, which, when crys-tallised from aqueous alcohol, melts at 46O. Hoogewerff and vanDorp give the melting point as 4 0 4 2 O . The substance is verysoluble in most organic solvents.This compound may be alsoconveniently isolated from the mixture obtained by heatingd-camphorimide, potassium hydroxide, and methyl iodide, by treat-ment with dilute sodium hydroxide solution in order to removeunchanged camphorimide, and crystallising the residue from dilutealcohol. The following determinations of rotatory power were made :Solvent. Weight in 25 C.C. a, in 2-dcm. tube. [ale.Alcohol ............ 0.6088 gram +0'54 " +11'1"), .............. 0.7843 ,) 0.69 11 -0 ,, ............... 0.8887 ), 0-81 11 '4Acetone .......... 0 *7070 , , 0'45 8.0,) ............ 1 -0365 ), 0'665 8.0, , ............... 1.0607 ,) 0.96 11.3d-Camphore thylirnide, c,H,,<~~>N co E t.d-Camphorimide (5 grams), 1.125N-potassium hydroxide (27.2c.c.), and ethyl iodide (4.4 grams) were heated together on thewater-bath for two hours ; after filtration, the alcohol was evaporatedoff, and the residual sweet-smelling oil washed with dilute sodiumhydroxide. The required ethyl derivative remained as an almostcolourless solid, which crystallised from dilute alcohol in long, whiteneedles, melting at 5 1 - 5 2 O ; the following determinations ofrotatory power were made :Solvent.Weight in 25 C.C. a, in 2-dcm. tube.Alcohol ............... 0.5216 gram + 052" ............... 0 -5370 , , 0.54), ............... 0.7588 ,, 0.76,) ............... 0'9757 , , 0.955Acetone ............ 0.5886 ,, 0.395,, ............ 0.7348 ,, 0 '52 ............ 1 '1890 ,) 0 -81 9 )[a],. + 12'4"12.612.512.58'48.88 '5Both the methyl and ethyl derivatives of d-camphorimide arepractically inactive in benzene solutions.d-Camphorb enzyZimi.de.This substance was obtained by Hoogewerff and van Dorp (loc.cit.) by heating benzylammonium camphorbenzylamate ; it is morereadily obtained by heating d-camphorimide (5 grams) with 1*125N-alcoholic potash (27.2 c.c.) and benzyl chloride (3.5 grams) on thewater-bath for two hours, evaporating off the alcohol, and addingdilute sodium hydroxide.An almost quantitative yield of thesolid product is obtained, which, after crystallisation from dilutDERIVATIVES OF D-CAM PHORIMIDE. 2241alcohol, melts at 60-62O. The following determinations of rotatorypower were made:Solvent. Weight in 25 C.C.Alcohol.. .............0'4539 gram) ) ............... 0.5776 , ,), ............... 0'8032 ,,Acetone ............ 0'7067 ) )), ............ 0.7358 ) ))) ............ 0,8361 ,,,, ............ o m 4 a ,,Benzene ............ 05476 ),)) ............ 0.9557 ,)aD in 2-dcni. tube.+ 0-46"0-560 -780.670.710.8150'940 -230.37[a],.-!- 12.7"12'112.111.912'012.211'95 - 24.8As in the previous cases the specific rotatory power is muchsmaller in benzene than in alcohol or acetone solutions.d-Camphor-p+itrob enzylimide, C,H,,(CO>N*CH,*C,H,.NO,. coCamphorimide (5 grams) dissolved in 1*125N-alcoholic potash(22.5 c.c.) wits heated with pnitrobenzyl chloride (4.75 grams) for ashort time on the water-bath; after separating the alcohol andtreating with dilute sodium hydroxide, the required derivative wasobtained as a yellow solid, which, after crystallisation from alcohol,formed yellow needles, melting at 133O :0.1985 gave 0.4709 CO, and 0.1142 H,O.The following determinations of rotatory power were made :Solvent. Weight in 25 C.C.a, i n 2-dcm. tubes. [.ID.Acetone ............ 0'5071 gram + 0 -48" + i i w) ) ............ 0.6795 ), 0'67 12.3), ............ 0.7848 ,) 0.775 12.3Benzene ............ 0.5630 ,) 0.115 2.6), ........... 0.9928 ,, 0.225 2.8The rotatory power has again a smaller value in benzene than inC= 64.69 ; H= 6.39.CllH2,04N2 requires C = 64.54 ; H = 6-33 per cent.acetone solutions.d-Camphorsodioimide, C,H,,<CO>NNa. coThis substance separates aa a white, flocculent mass on warminga solution of sodium (0.63 gram) in alcohol (2 c.c.) and benzene(5 c.c.), with addition of d-camphorimide (5 grams) dissolved inbenzene (20 c.c.); after collection and drying in a vacuum, thesubstance was analysed :0.6025 gave 0.1990 Na#04. Na= 10.70.The compound is readily soluble in water or alcohol, and is atC,,HI4O,NNa requires Na = 11.33 per cent.once decompoaed by acids.UNIVERSITY CHEMICAL LABORATORY,CAMBRIDGE