SOME STUDENT EXPERIMENTS in and out of the CYCLOPARAFFIN SERIES E. C. WAGNER University of Pennsylvania, Philadelphia, Pennsylvania
The nine experiments presented belov use cyclohexanol as the starting material and illustrate a number of functional reactions which are met in both the aliphatic and the alicyclic series. They may be used as optional relacements for corresponding exfieriments commonly performed with aliphatic compounds, with a consequent increase in the ~arietyand scope of the laboratory exercises and in the student's appreciation of the generality of certain reactions. There are exemfilified also the following more profuund structural changes: (1) ring-rupture, m'th @sage from the alicyclic to the aliphatic series, (2) ring-closure,with passage from the aliphatic to the alicyclic series, and (3) the passage from the cyclofarafin to the aromatic series by introduction of three double bonds. These instructiere exercises are not ordinarily included in elementary laboratory courses. They require no special apparatus and are well m'thin the manipulative abilities of undergraduate students.
(3) Oridation of cyclohcxanol to adipic acid; oxidation of a (4)
(5)
(6) (7) (8) (9)
secondary alcohol, through the ketone, to carboxylic acid. Preparation of cyclopcntanonefrom &pic acid; the preparation of a ketone from the barium salt of a carhoxylic acid. Preparation gf cyclopentanom-2,4-dinitrophnylhydramne; the preparation of an identifying derivative of a ketone. Preparation oj cyclohexylbrolnide from cycbhexanol; the replacement of alcoholic hydroxyl by halogen. Preparation o j 1.2-dil~omocycloheranefrom cycbhaxm; the saturation of an olefinic bond by bromine. Preparation of cydohezanone-&me from cycbhexanom; the preparation of the o x h e of a ketone. Reduction of cyclohexanone-&me to cycbhexylamine; the preparation of a primary amine by reduction of an oxime.
Incidental to the immediate purpose of experiment 3 is the f a d that the oxidation involves ring-rupture with formation of an aliphatic compound; since cyclohexanol is prepared by hydrogenation of phenol there is illustrated here the passage from the aromatic to the aliphatic series. Experiment 4, which yields a ketone EVERAL cycloparaftin hydrocarbons, notably cy- from a carboxylic acid by a general method, further clopentane and cyclohexane, and their simple de- illustrates a method of ring-closure which is familiar in rivatives, are so similar chemically to correspond- the passage from the aliphatic to the alicyclic series, ing aliphatic compounds that a number of the familiar in this case with a descent from Csto Cs. Experiment experiments which illustrate important general aliphatic 7, primarily the saturation of a double bond by bromine, reactions can be carried out interchangeably in either includes outline directions by which the exercise may series. The substitution of alicyclic for aliphatic com- be extended to show the fassage from the alicyclic to the pounds in the study of such reactions is entirely feasible aromatic series, by the path: cyclohexene -+ dibromousing as the starting material cyclohexanol (hexahydro- cyclohexane + cyclohexadiene -+dibromocyclophenol, "hexalin"), which is now inexpensive, and hexene +benzene. This illustrates a second common which chemically is a typical secondary alcohol. The method (cf. experiment 1) for introduction of double introduction of several such exercises into the laboratory bonds. It shows the sudden loss in the ordmary uncourse will give students some first-hand acquaintance saturated properties upon introduction of the third with a series of compounds known in many instances double bond, and opens the way for an instructive cononly on the pages of their textbooks. It will tend to sideration of the experimental researches of Baeyer break down the somewhat artificial boundaries within and others on the structure of benzene (1). which the student unconsciously segregates his knowlIn the preparation of the experiments the pertinent edge of the aliphatic and the several carbocyclic series, literature has been examined, and it is believed that the and should strengthen his appreciation of the degree of procedures chosen, in several cases after comparative generality of certain functional reactions. trials, are those hest adapted to student use. Though a The experiments, and the general reactions they majority of the preparations are described in "Organic illustrate, are as follows. Syntheses," the procedures were not in all cases found suitable to the present purpose, and in a number of (1) Preperetion of cycbhexae from cyclohemnol; the dehydra- instances some changes in apparatus and manipulation tion of an alcohol to an olefin. (2) Oridation of cyclohexanol to cyclohexanone; the oxidation were necessitated by the reduction of the operating scale to one-fifth to one-twentieth of that soecified. of a secondam alcohol to a ketone.
S
When the procedures of "Organic Syntheses" are to be used, detailed directions are omitted, references to the recently published collective volume or to subsequent annual volumes being given, together with minor changes shown by trial to be advisable. The yields and physical constants stated are those obtained by the procedures specified. Physical constants quoted from Beilstein or from International Critical Tables are indicated, respectively, (B.) or (Z.C.T.). Where the use of a fractionating column is recommended reference is made to a column of the size described in a recent paper (2). (1)
INTRODUCTION OF AN OLEFINIC BOND BY REMOVAL OF THE ELEMENTS O F WATER FROM AN ALCOHOL; THE PREPARATION OF CYCLOHEXENE FROM CYCWHEXANOL
Dehydration of cyclohexanol to cyclohexene by catalytic action of a small amount of sulfuric acid was reported by Senderens (3), whose method was used by Osterberg and Kendall (4), and appears also in "Organic Syntheses" (5). Other dehydrating agents are discussed by Osterberg and Kendall. Boudroux (6) obtained high yields by use of phosphoric acid at 160". The dehydration may be effected also by gasphase catalysis using alumina, etc. P R O C E D ~ : Follow the directions given in "Organic Syntheses" (5). Use 30 grams of cydohexanol and 1 cc. of conc. sulfuric acid in a 200-cc. flask surmounted by a short fractionating column, with condenser attached (no thermometer is required a t the head of the column). After drying the product as described, distil it from the original apparatus (with thermometer now in place), collecting the fraction which boils 82-8.3.7" car. The yield is about 70%.
The complete purification of cyclohexene was described by Waterman and van Westen (7), who found the boiling point to be 82.8'. Material made by the above method, after two distillations through a 3-ball Snyder column, boiled 83-83.2' cor. The unsaturation of cyclohexene is readily shown by the usual tests. (2) THE OXIDATION O F A SECONDARY ALCOHOL TO A KETONE; THE PREPARATION O F CYCLOHEXANONE FROM CYCLOHEXANOL Oxidation of cyclohexanol to cyclohexanone by means of chromic acid was outlined by Baeyer (8). The procedure was improved by Osterberg and Kendall (4), whose method is given below essentially unchanged. P R O C E D ~ : Transfer 25 grams of cyclohexanol to a 200-cc. flask, and chill in ice. Add gradually, with thorough mixing and chilline. -. 9 cc. of mnc. sulfuric acid. With the same orecautions add in 2 cc. portions a cooled solution of 25 grnms of sodium dichromate and 9 ec. of conc. sulfuric acid in 40 cc of water; this should require about an hour. Attach a reflu condenser, and heat the mixture for two hours on a water-hath. Cool the liquid, and extract with about 100 cc. of ether, used in three portions. Dry the ether extracts with anhydrous potassium carbonate, a t e r with suction to remove the bulky mass of drying agent, and transfer the extract to the flask of a fractionating outfit. Distil off the ether, and fractionate the residue slowly, collecting as cydohexasone the fraction boiling from 150 ~~
~
to 158" (cor.), and as unchanged cyclohexanol anything which distils fram 158 to 168".*
The yield of cyclohexanone is about 75% of the theoretical. The pure compound boils at 156.7' cor., and has the specific gravity 0.949 (=O/r). Cyclohexanone may be identified by preparation of the 2,4dinitrophenylhydrazone (m. p. 160") as described for cyclopentanone in experiment 5, or of the oxime (m. p. 88') prepared as described in experiment 8.
(3)
THE OXIDATION OF A SECONDARY ALCOHOL TO A CARBOXYLIC ACID VIA THE KETONE; PREPARATION OF ADIPIC Acm FROM CYCWHEXANOL
When cyclohexanol is oxidized more strongly than in experiment 2 the iirst-formed ketone is attacked in typical manner, with rupture of the carbon chain between the carbonyl carbon and an adjacent carbon atom, both of which are oxidized to carboxyl groups. The main product is adipic acid, HOOC(CHJ4COOH. Smaller amounts of several lower acids (glntaric, succinic, oxalic, and apparently monocarboxylic acids also) are formed as a result of incidental ring-rupture at other points. The same iinal results will be obtained whether the starting material is cyclohexanol or cyclohexanone. Oxidation by nitric acid was described by Bouveanlt and Locquin (9). An improvement of the method was patented by the Dentsche Hydrierwerke A.-G. and is now given in "Organic Syntheses" (10). Trials have shown the permanganate oxidation method of Mannich and Hancu (11) to be more convenient for preparation of small amounts of adipic acid. The oxidation, conducted in a large volume of water, is a mild reaction which requires no regulation nor provision for the disposal of toxic fumes. The modified procedure of Braun and Lemke (12), using a restricted volume (with efficient stirring, control of temperature, and gradual addition of solid permanganate), was found to offer no real advantage over the simpler method of Mannich and Hancn. The yield by permanganate oxidation (80% or more) is distinctly higher than by nitric acid oxidation (about 60%), but the latter method is more useful for preparation of larger quantities of adipic acid. P R O C E D ~ E : To a solution of 15 grams of sodium carbonate in 300 cc. of water in a 2-liter flask add 20 grams of cydohexanol. During about 15 minutes introduce a cooled solution of 90 g r a m s of potassium permanganate in 1500 cc. of water. Allow the mixture to stand a t room temperature, with occasional shaking, f o r several days. Filter with suction, extract the mass of hydrated manganese dioxide with water, and evaporate the combined filtrates rapidly t o a volume of a b u t 200 cc. Filter if not dear. transfer to a beaker on which the 150-cc.level has been marked. and evaporate t o this volume. Chill the solution in ice and (in a hood) add concentrated hydrochloric acid cauliously until the mixture is acid, and then 30 cc. of
-
* A column is necessary to retard distillation of unchanged cyclohexanol (b. p. 161.5') with the cydohexanone (b. p. 156.7'), and a t hest the separation is imperfect. If the high-boiling residue is tw small to operate the column, it may he distilled from a 10-cc. side-arm flask,and the 158-168' fraction collected as cvclo-
the acid in excess. After an hour in the ice-bath filter off the crude adipic acid, wash with cold water, and dry. The product is white, but smells strongly of intermediate fatty acids apparently present as impurities. The yield is about SOY0, T o recrystallize, dissolve the crude acid in about twice its weight of hot water, add charcoal, and boil (in a hood) until the rancid odor in the steam hecomes faint, keeping the volume constant by addition of water. Filter throuah a heated funnel. and chill the filtrate in ice. with stirring. he yield of nearly pure acid is about 75% a i d the m. p. about 1509
suggested by Brady and Elsmie (21), and was established by Allen (22), who devised a satisfactory general procedure for their preparation and characterized 58 carbonyl compounds in this way. Another procedure was devised bv Bradv (23). . . The reaeent condenses with carbonyl compounds even in presence of considerable minerd acid, $elding producL which are colored, highly crystalline, sparingly soluble (24), and readily obtained pure.
.
-
Adipic acid when pure melts at 151' (I.C.T.),* PROCEDUR~: (Method of Allen). Weigh in a tared 100-cc. and is distillable i n vacuo (B.). Its solubility in water Erlenmeyer flask 0.5 gram of cyclopentanone. Introduce 1.0 is 1.4 gram per 100 cc. a t 15'. It can be &stallized gram of 2.4-dinitrophenylhydrazine and 60 cc. of 95% alcohol. satisfactorilv from conc. nitric acid. one recnrstalliza- Heat t o boilina on a water-bath, add 1 cc. of conc. h v d r d o r i c tion a product of m. p. 15112' (10). ' acid. and boil the liauid . ..eeutlv. until evervthinn . dissaives. ~ -addinn . For preparation of adipic acid from cyclohexanone marc nlcohol 1 cc. a t a time if necessary. Chill the solution, filter by oxidation with perm&ganate see ~osenlew(14) off the precipitate, and r a s h with a little icc-cold alcohul. Dry a t 100"and determine the melting paint. and also Blaise and Koehler (15). The yield is practically theoretical. The derivative (4) THE FORMATION OF A gETONE FROM THE BARIUM melts a t 142'. SALT O F AN ACID; THE CONVERSION OF ADlPIC Allen (22) describes the preparation of the reagent ACID TO CYCLOPENTANONE from Z,4-dinitrochloro(bromo)henzeue and hvdrazine The most general application of the essential reaction, (25). The reaction is good example of repfacement COz HzO, involves dry of "activated" aromatic halogen, and is satisfactory as a 2RCOOH + R C 0 . R distillation of the calcium or barium salts of the acid student experiment. (or of mixed acids). Morgan and Holmes (16) prepared in this way a number of methylketones (CHsC0.(6) THE REPLACEMENT OF ALCOHOLIC H Y D R O X ~BY HALOGEN; THE PREPARATION O F CYCWHEXYLC.H2, + in which nranged from 7 to 19. With volatile acids a vapor-phase catalytic process may be used BROMIDE FROM CYCLOHEXANOL (17). In the case of adipic acid the desired decomposiFor preparation of cyclohexylbromide from cyclotion of the barium salt occurs below the boiling point of hexanol Baeyer (8) used fuming hydrobromic acid the acid. It is therefore possible, by heating to the de- under pressure, Wahl and Meyer (26) used excess of composition temperature with only a small amount of the acid under reflnx, and Hope and Perkin (27) embarium oxide or hydroxide, to effect the progressive ployed in the same way a saturated solution of hydroconversion of the acid, through its barium salt, to gen bromide in glacial acetic acid. Better results can cyclopentanone, which distils out. This excellent be obtained, according to Hiers and Adams (28), by procedure appeared as a Baeyer and Co. patent (la), action of phosphorus tribromide on cyclohexanol, as is described by Vanino (19), and is given essentially first used by Freundler and Damond (29), modified by unchanged, hut with useful comments, in "Organic Kohler and Bnrnley (30), and by Krause and Pohland Syntheses" (20). (31), whose procedure is described below.
-
+
+
PROCEDURE: Follow the directions given in "Organic Syntheses" (20). Use for the reaction a ground mixture of 20 t o 25 grams of adipic acid and 1.5 gram of barium hydroxide, contained in a 125-cc.side-arm flask with the bulb nearly immersed in a sand-bath. Raise the temperature so that the molten charge reaches 290" in about 40 minutes. To the distillate add solid sodium or potassium carbonate until the aqueous layer is saturated, separate the ketone layer, and dry over night with calcium chloride.? Redistil the oroduct. collectine - as cvclonentanone . . the portion which boils 128-132" =or.
The yield is about 70%. The boiling point of pure cyclopentauone is 130.6°, and the sp&fic 0.951 (2%) (I.C.T.). (5)
THE PREPARATION O F AN IDENTIFYING DERIVATIVE OF A KETONE: CYCLOPENTANONE-Z,4DINITROPHENYLHYDRAZONE
The usefulness of the Z,4-dinitrophenylhydrazonesas identifying derivatives of carbonyl compounds was * Other recorded values (13)rauae from 149' t o 153.5'. t This treatment rcmov& baccsof adipic acid, nnd salts out
the krtaoe. without thc low of product which attends the washing with water and aqueous nlkaliasdirect:d in "Organic Syntheses."
~~
~~~~-
a
PROCEDURE: Provide a dry 250-cc.flask with a two-hole stopper carrying a small dropping funnel and a calcium chloride tube. the latter connected with a sodium hydroxide trap. Weigh 25 grams of cyclohexanol into the flask, cool in ice. and add drop by drop from the funnel 34 grams (1.5 times theory) of phosphorus tribromide,* with thorough mixing and continual chilling; the reaction mixture should he kept near 0 4 t o minimize formation of cyclohexeue. Allow t o stand several hours in the ice-bath. then a t room temperature over night, and finally heat for 30 minutes on the water-hath. Pour the mixture slowly into chipped ice (in the hood). Separate the layer of cyclohexylbromide, wash with 5% sodium hydroxide solution, and then with water. Dry with anhydrous calcium chloride until the liquid is clear. Decant into a 125-cc. Claisen flask and distil under reduced pressure.
Reported boiling points for various pressures are as follows: 113-116° (150 mm.), 69-71' (30 mm.), 61-62" (20mm.), 52.5" (13.5 mm.) (27), (28), (29), (31). Under ordinary pressure cyclohexylbromide boils at * For preparation of phospliarus tribromide from red phosAND REID, J.Am. Chem. Soc.. phorus and bromine see EDWARDS 52,3239 (1930).
165.5" (I.C.T.), but with partial decomposition. The yield is 80% or more; it is decreased by formation of some cyclohexylphosphite (29). Cyclohexylbromide resembles the alkyl halides of comparable molecular weight in odor, etc., though the bromine atom (unlike that in cyclopentyl- or cycloheptylbromide) is firmly held (32). With magnesium cyclohexylbromide yields the Grignard compound (together with some cyclohexene and dicyclohexyl) and this can be used in familiar ways. By action of dry carbon dioxide there can be obtained good yields of cyclohexanecarboxylic (hexahydrobenzoic) acid (33). (7) THE SATURATION OF AN OLEFINIC BOND BY HALOGEN; THE PREPARATION OF 1,2-DIBROMOCYCLOHEXANE PROM CYCLOHEXENE
The compound 1,Z-dibromocyclohexane is best prepared by saturation of cyclohexene with bromine; attempts to obtain it by direct brominatiou of cyclohexylbromide were not successful (34). P R O C E D ~ E : Follow the directions given in "Organic Syntheses" (35), using one-fifth the quantities specified. Use for the reaction a 500-cc. flask; the mechanical stirrer may be omitted, the reaction mixture being shaken by hand during the addition. Reported bailing points a t various pressures (other than that stated) are as fallows: 145-6" (100 mm.). 116' (29 mm.), 101-2' (13 mm.). The compound cannot he distilled under ordinary pressure.
THE INTRODUCTION OF DOUBLE BONDS BY ABSTRACTION OF HYDROGEN BROMIDE; CYCLOHEXADIENE AND BENZENE PROM 1,z-DIBROMOCYCLOHEXANE
This interesting series of reactions was described by Crossley (36). It involves removal of 2HBr from dibromocyclohexane by heating with quinoline, partial saturation of the conjugate system of the resulting cyclohexadiene by bromine (l,Caddition), and finally the removal of 2HBr by means of quinoline, with introduction of a second and third double bond and formation of benzene. The experiment is instructive and is manipulatively simple, though the yields are small. The quinoline can be recovered. An outline of the procedure follows. Upon heating 1,2-dibromocyclohexane with twice its weight of quinoline to 178' hydrogen bromide is removed, and the distillate, collected up to 100°, consists largely of cyclohexadiene-1,3.* After redistillation from some quinoline, washing with dilute sulfuric acid, drying with calcium chloride, and distillation from sodium, the product boils at 81.5-82'. The yield is rather small. Cyclohexadiene polymerizes in sunlight, becoming viscous, and takes up atmospheric oxygen to form (eventually) an explosive sirup. When cyclohexadiene-l,3 in chilled chloroform solution is treated very slowly with one mol of bromine in chloroform, there occurs vigorous addition of the 1-btype once regarded as characteristic of conjugated
systems. Upon evaporation of the solvent, and reaystallizatiou of the residue from ligroin, there is obtained 1,4-dibromocyclohexene-2, a crystalline solid of melting point 108-9'. By heating 1,4-dibromocyclohexene-Zwith twice its weight of quinoline as outlined above, the distillate up to 90" consists largely of benzene, which after drying The yield is with calcium chloride distils at 80-1'. small, but the product is readily recognized. To identify with certainty, 3 drops may be converted into m-dinitrobenzene, m. p. 8g0, as described by Mulliken (37). (8)
THE PREPARATION OF CYCLOHEXANONE-OXIME FROM CYCLOHEXANONE
Preparation of this oxime has been described by Baeyer (a), Osterberg and Kendall (4), and in "Organic Syntheses" (38); yields are uniformly high. The procedure given below is that of Osterberg and Kendall. PROCEDURE: Chill in ice a mixture of 10 nrams of cvdoheranone, 10 grams of sodium bicarbonate, and 35 cc. of water. Dissolve 7.1 grams of hydroxylamine hydrochloride in 15 cc. of water, and add in small portions t o the ketone mixture, with stirring and chilling. Allow to stand for about an hour in ice, and filter off the separated oxime. Wash twice with ice water, and dry in a vacuum desiccator or in the air. The yield is about 10 prams, or nearly 90%. To purify the product dissolve it in boiling ligroin, using 4 cc. for each gram of oxime, and chill the solution in ice. The yield of pure oxime (m. p. 8SC)is about 75%.
(9) THE AMINE;
REDUCTION O P AN OXIME TO A PRIMARY THE PREPARATION O F CYCLOHEXYLAMINE PROM CYCLOHEXANONE-OXIME
Cyclohexylamine has been made by catalytic hydrogenation of. aniline (39), (40), of cyclohexanone-hydrazone (41), of cyclohexanone-oxime (42), and also by action of liquid ammonia upon cyclohexanol (43). The best laboratory method is the chemical reduction of the oxime by sodium and alcohol. Earlier procedures (4), (8) use a large excess of sodium and alcohol, but state no yields. The procedure of "Organic Syntheses" (44) for reduction of heptaldehyde-oxime (and recommended also for other oximes including that of cyclohexanone) specifies a more moderate excess of reducing agent. The similar reduction of menthoneoxime (45) requires even less sodium, and the same conditions were found to serve for preparation of cyclohexylamine more economically and in satisfactory yield.
PROCEDURE: Follow the directions given in "Organic Syn. 10 grams of cyclohexanonetheses" (44). Use a 5 0 0 ~ flask, oaime, 150 cc. of dehydrated alcohol, and 15 grams of sodium. If any sodium remains undissolved, add finally a little more alcohol. I n the receiver for the steam distillate put 20 cc. of 6N hydrochloric acid; after the distillation evaporate this liquid to dryness, dry a t 100; and weigh the crystalline residue as crude cyclohexylamine hydrochloride. The yield is about SO$& Reserve 0.2 mam for preparation of the piaate and purify the . "St by either of the following methods, one yielding the hydro' T h i s product, according t o H ~ R I E SW , ILLSTA~~ Ct~al. , (see Beilsteiu, 4th ed.. Vol. V, p. 113; Suppl. vol. V, p. 61). is a m ~ x - chloride and the other the base. ture of cydohexadiene-1.3 with cvclohexene, l-hrom~c~clohex- (a) To obtain pure cyclohexylamine hydrochloride (8) dissolve the crude salt in the least hot alcohol, filter quickly, add a ene-1 and-benzene.
large excess (10-20 volumes) of ether, and chill in ice. Filter off the separated amine salt, wash with cold ether, and dry. The recovery is about 75%. The melting paint is 204'. (b) To obtain cyclohexylamine (the base) dissolve the crude hydrochloride in about 10 cc. of water, make alkaline with strong sodium hydroxide solution, and extract the separated amine in ether. Dry the extract thoroughly over solid sodium or potassium hydroxide,* transfer the ether solution to the flask of a fractionating ouffit, and distil off the ether. When the temperature of distillation exceeds 125', attach as receiver a small side-arm flask (tared) with the outlet protected by a soda-lime tuhe (cycloheaylamine absorbs carbon dioxide readily from the air). Collect as product the portion which boils 13W5". The yield is about 55%.t With the least possible exposure to the air transfer the product, through a miniature thistle-tube, to a small sealing bottle.
Cyclohexylamine is a strong organic base with ammoniacal odor. The boiling point is variously given (B.), values ranging from 130 to 13S0. Made as described above the product boiled almost wholly a t 133-1' (uncor.). C Y C L O ~ X ~ W L MPICRATE. INE Dissolve 0.2 gram of cyclohexylamine hydrochloride, 0.25 gram of pinic acid, and 0.2 gram of crystallized sodium acetate in 10 cc. of hot water, and chill the solution in ice. Filter with suction, and wash the picrate with cold water. Dry, weigh, and determine the melting point. The yield is about 0.3 gram, and the melting point 155-6' (158-9' cor.). This picrate has apparently not been reported hitherto.
As an alternative experiment, menthone-oxime (46) mav he reduced to menthvlamine (45). This is removed by steam distillation; as in &above procedure, and the distillate liquid concentrated to about 100 cc., filtered, evaporated further to 50 cc., and chilled. The amine salt crystallizes out in a yield of 80% or more, depending upon the purity of the oxime. The hydrochloride does not melt. I t may be transposed to the diiKcultly soluble picrate (47) of m. p. 173'.
* According to HIERSAND ADAMS(39) cyclohexylamine forms with water a constant-boiling mixture (94-5' a t 746 mm.): .. complete drying requircj us< of ~ n e t d ~sodium. ic t A yield of 57% was obuincd whm the aminr was dirtilled through a small Vipeux column (2) of about 1 cc. hold-"1,. LITERATURE CITED
(1) COHEN."Organic Chemistry for Advanced Students," 5th ed., 1928, Arnold and Co., London, Vol. 11, pp. 440-53; HENRICH,"Theories of Organic Chemistry," transl. by JOHNSON AND H.um, John Wiley and Sons, Inc., New York, 1922, pp.24-8. s WAGNER, J. CHEM.EDUC.,9, 12-1 (Jan., (2) S m o ~ AND 1932). (3) SBMERENS,Compt. rend., 154, I , 1169 (1912). J. Am. Chem. Soc., 42,2616 (4) OSTERBERG AND KENDALL, 26 (1920). (5) "Organic Syntheses," Collective Volume I, GILMAN. editor; John Wiley and Sons, Inc., New York, 1932, p. 177. (6) Bouonoux, Ann. chim. [10]. 11,51142 (1929). N VAN WESTEN.Rec. trav. chim., 48, 637 (7) W A T E ~ AAND 11010\
(8) BABYER,Ann., 278,100 (1894). AND LOCQUIN, B d l . sac. chim. [4],3,43741 (9) BOUVEAULT (1-PnRl - ., . -(10) Ger. Pat. 473,960 (1926); "Organic Syntheses." Coll. Vol. I. D. 18: cf. "Oreanic Syntheses." Vol. V, D. 9: and EDWARDS 3. Am. c h . SOL., 52,3238 (1930j.ANDREID, AND HANCU, Ber., 41, 575 (1908). (11 MANNICH AND LEMKE,ihid., 55,352636 (1922). (121 BRAUN \
(13) Beilstein, 4th ed., Vol. 11, p. 651; see also BmE AND SUDBOEOIJGH, J. Indian Inst. Sci., 8, 89 (1925); Chem. Abstr., 19,3252 (1925). Be?., 39,2202 (1906). (14) ROSENLEW. B d l . sot. chim. [4],5,682 (1909). (15) BLAISEAND KOEHLER, AND HOLMES, 1.SOC.Chem.Ind., 44,108 (1925). (16) MORGAN (17) SENDERENS, Compt. rend., 146, 1212 (1908); Bull. soc. chim. 141, 3, 824 (1908); see experiment suggested by CONANT, "Organic Chemistry," The Macmillan Co., New York, 1928, p. 105; also KOCHAKIAN,J. CHEM.EDUC.,9, 1649 (Sept., 1932). (18) Ger. Pat. 256,622; Friedl., 11, 49 (1913); HARRIESAND WAGNER, Ann., 410, 2 9 4 0 (1915); VAVONAND APCHIE,Bull. soc. chim. 141.43.667-77 (1928). . .. , , , (19) VANINO,"Praparative Chemie," 2nd ed., F. Enke, Stuttaart. Val. 11. 1923. D. 79. (20) ';organic syntheses," Coll. Vol. I, p. 187. (21) BKADY AND ELSMIE, Analyst, 51,77 1926) (22) ALLEN,J. Am. Chem. Soc., 52,2955 [1930): (23) BEADY, J. Chem. Soc., 1931,756. (24) Acetone is precipitated quantitatively: Bthow, Science, 61,344 (1925). (25) P ~ G O T T IGazz. , chim. ifnl.,24, 555 (1894). (26) WAHLAND MEYER,Bull. SOC. chim. 141, 3, 957 (1908); Compt. rend., 145,193 (1907). (27) HOPEAND PERKIN,J. Chem. Soc., 95,1360 (1909). (28) HIensnNn ADAMS, J. Am. Chem. Soc., 48,2388 (1926). AND DAMOND. Combt. rend.. 141.593 (1905). (29) FREUNDLER
.
.
(31j KRAUSE AND POHLAND; Ber., 57,532 ( m k ) . (32) LOEVENICH, et al., ibid., 62, 3084 (1929). (33) WAHLAND MEYER,Ref. (28). p. 958; HIERSAND ADAMS, AND ZOELLNER. J. Am. Chem. Soc.. Ref. 128). n. 2390: GILMAN 53,1945'~1i31). B d l . SOL. chim. [4], 9, 592 (34) B o u ~ n o u xAND TABOURY, 11011)
p.
zuu. (38) (39) (40) (41) (42j (43)
(10Rn> ,-"--,.
"Drganic Syntheses." Vol. XI. 1931, p. 54. HIERs AND ADAMS, Ber., 59,162 (1926). Ger. Pat. 481,984 (1926); Brit. Pat. 305,507 (1927), etc. M A ~ EComat. . rend.. 174.465 (19221. AMORO~X, ch'em.-ztg.;35, i92 (i911): GUYOTAND FOURNIER, Bull. soc. chim. 141. 47, 203
(44) "Drganic Syntheses." Val. XI, 1931, p. 58. (45) WALLACH AND KUTHE.Ann., 276, 301 (1893); R~JNTER, Bull. soc. chim. 131, 16, 1283 (1896). (46) H. L. FISHER, "Laboratory Manual of Organic Chemistry," John Wiley and Sons. Inc., New York, 3rd ed., 1931, p.
--
l(14 -.
(47) READ, COOK,AND SHANNON, J. Chem. Soc., 1926, 222334.
