reaction. D-Fructose diethyl mercaptal exists and has been made by an indirect method.1° The hexosamines are essentially insoluble in concentrated hydrochloric acid and the procedure is not applicable to them. The acetylated diethyl mercsptals of the ethyl" and methy111.12 esters of galacturonic acid have been recorded. An obvious disadvantage of the method is t h y odor of the ethyl mercaptan but this can be minimized by the employment of small quantities of material and by the use of good fume cupboards. The purified substances are odorless. TABLEI CHAKACTERIZINC; PROPERTIES OF THE KNOWNv1lLl.Y ACWYI.ATED DIETHYLMERCAPTAISOF ALnOMoKosAcCHARIDRS [a]20-%
Fully ncetylated diethyl mercaptal of
o-Arabinose" L-Arabinosc"
[)-Xylose" u-Lyxosed i)-Glucose~ 11-Galactox> ( triiucirphous 1'
Iksuxy-L-galact osc il,-fucost.)" u-hlari nose' ti-~esoxy-L-manii~ (m-liani~s~ nose) D-Gluco-D-gulo-heptose' o-Gala-L-glz(co-heptosek
M p , o c
80 79-80 46-48 3-37 45-47 76 5-77 80.5-81' 90 5-81
(c
< 5,
CHCIx)
+30" -30 fl.3 +40. +I1 +I 1
A
+I1 +I1
ti-
+ 5 f.32
'
59-81 -42 99-100 - 12 105 +27 145-146 D-Gala-L-manno- heptose^ 56 77 o-Manno-D-galn-heptose"' - 2.2 106 +30 D-Gala-L-gah-octosc" Methyl D-galacturonate",' 112.5-113.5 +20.5 Ethyl D-galacturonateP 80--81 +I1 a hl. L. Wolfrom, D. I. Weisblat, W. H. Zophy and S W. Waishrot, THIS JOURNAL, 63, 201 (1941). M . L. Wolfron! and Mildred R. Newlin, ibid., 52, 3619 (19801 Kef. 8. hl. L. Wolfrom and F. B. Moody, ibid., 62, 3 4 G (1940). e W. Schneider and Johanna Sepp, Ber.. 51, 220 (1918); &I. L. Wolfrom, THIS JOURNAL, 51, 2188 (1929); first nuclei difficult t o obtain but the deacetylated form crystallizes with ease. f M. L. Wolfrom, ibid., 52, 2464 (1930); L. H. Welsh and G. L. Keenan, ibid., 64, 183 (1942). 0 Stable form. M. L. Wolfrom and J. A. Orsino, ibid., 56, 985 (1934). N. W. Pirie, Biochem. J . , 30, 374 (1936); Mildred R. h-ewlin, Ph.D. dissertation, The Ohio State University (1932); in the publication of Pirie, L-rhamnose diethyl mercaptal tetraacetate is recorded incorrectly as being dextrorotatory. M. L Wolfrom, M. Konigsberg, F. B. Moody (and Mildred R . Newlin), THISJOURNAL, 62, 2348 (1940) ; higher sugar iiomenclature of C. S. Hudson, ihid., 60, 1537 (1938). R. M. Hann and C. S. Hudson, ibid., 56, 2080 (1934). R. M. Hann and C. S. Hudson, ibid., 59, 1898 (1937). ',, Edna Montgomery and C. S. Hudson, ibid., 56, 2463 (1934). R. M. H a m , W. D. Maclay and C. S. Hudson, zbzd.,61, 1270 (1939). Ref. 12. p Ref. 11.
+
'
(10) M. L. Wolfrom and A . 'Thompson, THISJOURNAL, 66, 880 ( 1934).
(11) R . J . Diinler arTd K . P. I.ink, ibid.,62, 1216 (1940). Campbell a n d K P. I.ink, . I . Bioi C h e w . . 110, 471 i 1937) ( 1 2 ) €I A
Experimental Identification of =Mannose as D-Mannose Diethyl Mercaptal Pentaacetate.-The general procedure employed was an adaptation of that reported previously8 from this Laboratory. D-Mannose (50 mg.) was dissolved in 0.5 cc. of concentrated hydrochloric acid (ca. 12 N ) in an icehath and 0.5 cc. of ethyl mercaptan added. The mixturr was stirred or shaken mechanically for one hour and was then neutralized in the cold with concentrated ammoniun; hydroxide (m. 15 )'%1 and concentrated t o dryness a t 40 under reduced pressure. The salt residue was dried by adding absolute ethanol and removing this by distillation under reduced pressure a t 40°, the process being repeated several times. The dried residue was treated with 3 cc. of a 2: 1 (by volume) mixture of acetic anhydride and dry pyridine. After standing overnight at room temperature, the solution was poured into 10 cc. of water and extracted twice with 10-cc. portions of chloroform. The chloroform extract was washed four times with 10 cc. of a saturated aqueous sodium bicarbonate solution and finally with water. The sirup obtained on solvent removal from tlic dried chloroform extract was crystallized from methanol solution by the gradual addition of water; yield of Dmannose diethyl mercaptal pentaacetate practically quantitative, m. p. 51-52'. Identification of D-Gdactose in a Crude Hydrolyzate.A fraction of solid material (50 mg.) obtained by the acid hydrolysis of a galactose-containing polysaccharide and containing cu. 25% of D-galactose (as determined by the mucic acid assay) was treated as described above and the product isolated in the same manner; yield of D-gaptosr diethyl mercaptal pentaacetate 15 mg., m. p. 78-79 . As a confirmatory derivative, the above acetate was deacetylated to D-galactose diethyl mercaptal. T o 9 mg. of the D-galactose diethyl mercaptal pentaacetate dissolved in 2 cc. of anhydrous methanol was added 0.5 cc. (cu. lo%, excess) of 0.2 N barium methoxide in methanol (prepared by refluxing barium oxide with anhydrous methanol) and the solution refluxed for one hour. Carbon dioxide gas was then introduced until precipitation was complete and the precipitated barium carbonate was removed by centrifugation. The residue obtained on solvent removal from the centrifugate was extracted with 2 cc. of warm ethanol (acetone is likewise useful as a solvent in which the sugar mercaptals have some solubility) and crystallized from aqueous ethanol; yield of D-galactose diethyl mercaptal 3 mg., m. p. 138-139' (micro stage). CHEMICAL LABORATORY THEOHIOSTATE UNIVERSITY COLUMBIJS, OHIO RECEIVED JANUARY 9, 1945
NE\\' COMPOUNDS Esters of Mesitoic Acid 2-Mesitoyl-4-methylphenyl Mesitoate.- A mixture of 22 g. of 2-mesitoyl-4-methylphenol' and 20 g. of mesitoyl chloride was warmed until hydrogen chloride ceased to be evolved. The reaction mixture was dissolved in ether, and the resulting solution washed successively with water, dilute sodium hydroxide solution and water. Evaporatiou of the ether left the ester as a solid which, after being recrystallized from ethanol, melted a t 135-136'; yield 32%;. A n d . Calcd. for Cg~H2~03: C, 80.97; H, 7.05. Found: C, 81.31; H, 7.09. Phenyl Mesitoate.-The phenyl ester was prepared in 83% yield from phenol and mesitoyl chloride. I t formed colorless needles; m. p, 37-38' (cor.). Anal. Calcd. for CtsHleOz: C, 79.97; H, 6.71. Found: C, 80.28; H, 6.75. (1) Fuson, Scott and Speck, THISJOURNAL, 63, 2845 (1941)
Procedure.-A vertical glass tulje, -16 min. tiy 450 ni~n. dimensions, was filled with glass heads and electrically heated so that a thermometer imbedded i n the glass heads was maintained a t 150'. Liquid 2,3-butanediol was dropped into the top of the tube a t the rate of 44 g. pcr hour while pliosgeiie gas was introduced i:ito the bottom of the tube a t the rate of 200 ml. per minute. The products nEPARTHlXXT OF CIIEMISTRY boiling above 1 j O 0 were collected a t the bottom i)f the UNIVERSITY OF ILLINOIS REYNOLD C. PUSON tube. The resulting material was heated, on a lmiling I J R I ~ A N A TLLINOIS , STANLEY R . SPECK water-liath under a reflux condenser, for two hours to coniplete the reaction. During the heating period copious R R C E I V E D N O V E M ~ 27, E R 1944 evolution of hydrogen chloride took place. The reiulting product was distilled at reduced pressure, a large fraction The Inner Carbonate of Z,3-Butanediol distilling a t SG" a t 8 rnni. pressure; yield, 75%. ,Inid. Calcd. for C~H,OJ: C, 51.7; H. 7.0. Fouiid: HamniondLand Mitchell* have patented methods for the C, 51.5; H, 7.1. preparation of the alkyl carbonates and chlorocarbonates Properties-The molecular weight in phenanthrciie was by the interaction of the aliphatic monohydric alcohols l l i i , ?I% 1.422f.3, d26, 1.129, b. p. 240' (740 niin.1. The and phosgene. These procedures have been applied by the present authors t o the interaction of 2,S-butanedid compound i i colorless and insoluble in water. It i i an exand phosgene. cellelit solvelit for cellulose nitrate and cellulose acetate. CHEMISTRY DEPARTMENT J. J . KOLFESRACH (1) J. A. Hammond, U. S. Patents 1,603,680 (October 19. 19%); 8-Naphthyl Mesitoak---This ester wdb p r i - p a r d in %if';. yield from rnesitoyl chloride and 8-naphthol. It crystallized from alcohol in colorless needles; m. p. 110-.-11:3" (cor.). Anal. Calcd. for C2J-I,,02: C, 82.73; 11, ii 2.7, Found: C, 82.12; I f , 6.37.
1,618,824 (February 22, 1927). ( 2 ) H. G. Mitchell, U. S. Patents I,FO.?,iOd (October 19, 1926); 1,R.M 1114 ( . 4 l l ~ ~ l9. i t lOl7j
iii
IO\VA ST.4TE CULLEGE X > l l ? S . I0n.A
IZFXEIVED DECEMBER 18, 1911
THE SYNTHESIS OF AMINO ACIDS FROM ACETAMIDOCYANOACETIC ESTER
Calcd. monohydrate: C, -49.25;H, 6.01. Found: C , -19.40; H, 3.8'3). Hydrolysis with sulfuric Sir: acid gave a 617, yield of dl-histidine, m. p. 38.3'. Recently considerable interest has been shown The dihydrochloride melted a t Z3Z0.3 The overin the preparation of amino acids from acetaniido- all yield of dl-histidine froin cane sugar was 18%. malonic ester. We have found that ethyl x e t Methyla tion of monothioethylene glycol with amidocyanoacetate ( I ) I possesses even greater dimethyl sulfate gave 80% of P-methylthioladvantages as a general reagent. Alkylation is ethanol. Chlorination with thionyl chloride and effected under the same conditions employed for condensation with I without isolation of the acetamidoinalonic ester.? Direct hydrolysis of methylthiolethyl chloride or chlorination with the condensation product proceeds in either acid hydrogen chloride followed by condensation with or basic media t o yield the amino ~ i t l . I gave 60% of the theoretical amount of ethyl cyacetatnido-a-cyano- y-rnethylthiolbutyrate ( II, CN cs R = methylthiolethyl), m. p. 118' (calcd. h', I I HCNHAc +RCSHAc --+RCHCOOH 11.47. Found: N, 11.62). Basic hydrolysis I I I gave 80% of recrystallized dZ-methionine. Thy COOEt COOEt 2" N-benzoyl derivative melted a t 150'. I I1 Alkylation of I with isopropyl bromide gave Alkylation of I with grariiine gave OSL;, of 667, of ethyl a-acetamido-aycyano-/3-methylbutyethyl a-acetaniido-a-cyanu-~-(3-i1idolyl~-propionrate (11, R = isopropyl), m. p. 149' (chlcd.: S , ate (11, R = skatyl), ni. p. 196-198' (calcd. 13.20. Found: Tu', 13.52). Alkaline hydrolysis N, 14.02, Found: N , 13.78). Alkaline hydroly- gave (55% of pure dl-valine, m. .p. 389-290'. sis gave dl-tryptophan, m. p. 2SS-29Oo (cor.). A Acid hydrolysis gave an 80% yield, but the 71% yield of pure amino acid was obtained from melting point was lower. The N-acetyl derivacrude indole. tive melted at 147' and the N-benzoyl derivativr When 4-chloromethylimidazole hydrochloride a t 131'. was condensed with I, a G G 7 , yield of ethyl Condensation of benzyl chloride with I gave a-acetamido-a-cyano-P-imidazolepropionate (11, 83% of ethyl a-acetamido-a-cyano-6-phenylproR = 4-imidazolemethyl), ni. p. 100-103' an- pionate (11, R = benzyl); rn. p. 134' (calcd. N , hydrous or 111' as monohydrate, was obtained ' l O . i . 3 . Found: N, 10.57). Hydrolysis with (calcd. anhydrous: N, 22.39. Found: N , 21.98. sodium hydroxide gave a 757, yield of dl-phenyl(1) Cerchez and Colesiu, Compt r e n d , 194, 1954 (1Y32) alanine, m. p. 2i5-277'. (2) (a) A l b e r t s o n Archer and Suter, TEISJ O W R N ~ L67, . 36 (19-15). (ti) Albertson and Archer, rbrd
67, 308 (1943)
( 3 ) Pyman, J . C k r m . SOL.,99, 1395 (1911).
