COMMUNICATIONS TO THE EDITOR
May, 1945
883
TABLE I POLYMETHYLENEDIAMINES B. p., *C.
Carbon, % Calcd. Found
Hydrogen, % Calcd. Pound
97-99 137-138 104.111 131-132 148-149 136-137 142-144
72.00. 75.00 73.68
14.00 14.06 14.03
1 mm.
72.28 75.03 73.40
...
14.36 14.35 14.27
...
...
...
... ...
75.00 76.05
74.93 76.30
14.00 14.08
14.25 14.51
...
sium phthalimide by the conventional procedures.'.' Hydrolysis of these compounds by hydrazine hydrate' was more satisfactory than hydrolysis by concentrated hydrochloric acid. The diamines are listed in Table I. They are colorless, viscous liquids, insoluble in water. They are hygroscofiic and absorb carbon dioxide from the air. Efforts to prepare the usual solid derivatives yielded oils which would not crystallize. The hydrochlorides were too hygroscopic to be of value as derivatives. (6) Muller and Kraus, Monalsh.. 61, 219 (1932). (7) Gabriel, Be?., 92, 1137 (1889). (8) Ing and Manske, J . Chcm. Soc., 2350 (1926).
H. E. FRENCH CHEMISTRYLAE~ORATORY H. E. UNGNMB UNIVERSITY OF MISSOURI J. E. P O = COLUMBIA, MISSOURI L. H. EILERS F~CEIVED MARCH14, 1945
Bh(8-alkoxyethyl) DSlenides Bis-( &methoxgethyl) Diee1enide.-A mixture of 28 g. of potassium sulfite and 9.5 g. of selenium in 300 ml. of 50% ethanol was digested under refiux for an hour. Four grams of anhydrous potassium carbonate and 11.3 ml. of methyl 2-bromoethyl ether in 12 ml. of ethanol were successively added and the refluxing was continued for two more hours. The mixture was acidified with excess 1 N
...
Nitrogen, % Calcd. Found
... ...
...
10.83 9.85
10.62 10.18
...
...
9.85
9.62
.*.
... ...
hydrochloric acid and then' oxidized with 70 ml. of 3% hydrogen peroxide, $added slowly with stirring. The diselenide separated out as 8 n orange red oil with a strong alliaceous odor. The oil was washed with warm water. centrifuged and fractionated under reduced pressure; b. Q. 124-126' (7mm.), yield 10 g. hopedies.-Bis-( @-rnethoxyethyl) diselenide is a yellow, vesicant oil with alliaceous odor; i, HnO, s. organic solvents. Bis-(8-ethoxyethyl) diselenide and bis-(8-butoxyethyl) diselenide also have been prepared. Both are yellow oils of unpleasant odor and are skin irritants. DATAON BIS-(@-ALKOXYRTHYL) DISELBNIDES Formula
OHttOISer 26.23
Found Boiling point dah
{.i:
n"D
.
6.29 124-126 7 1.596 1.5554
CiH18OiSer GzHisOaSer 31.57 31.43 5.97 5.89 135-137 6 1.451 1.5340
39.99 40. IO 7.28 7.39 175-177 6 1.303 1.5150
CHEM~CAL LABORATORY CATHOLIC UNIVERSITY OF AMERICA H.P.WARD WASHINGTON, D. C. I. LEOO'DONNELL~ RECEIVEDFEBRUARY 5, 1945 (1) Present address, St Mary's College, Winona, Minnesota.
COMMUNICATIONS T O T H E E D I T O R ORIENTED FIBERS OF SODIUM PECTATE
Sir: Although brief mention has been made in several places concerning X-ray diffraction investigations of pectin or pectin derivatives, interpretation of the data obtained has not been attempted. This lack of information concerning the structure of this important natural polymer is partly due to the difficulty of getting X-ray diffraction photographs with sufficient reflections to enable a structural analysis to be made. A short time ago it was noticed from X-ray powder photographs that sodium pectate is highly crystalline. Attempts were immediately made to produce sodium pectate fibers having molecular orientation. Best results were obtained by first making a pectic acid fiber and then converting it to the sodium salt. The pectic acid used was prepared in this Laboratory by the method of Baier
and Wilson' and'had an intrinsic viscosity of 3.8. A successful method for making well-oriented sodium pectate fibers consisted of titrating a 1% solution of pectic acid to a PH of 5.0 with sodium hydroxide. The resulting solution was then forced through a I-mm. nozzle into a coagulating bath consistiiig of 85% ethyl alcohol in 1 N hydrochloric acid. The resdlting wet fiber was strong enough to be handled readily. The hydrated fiber was held in a 60% alcoholic, 0:l N sodium hydroxide solution overnight and then immersed for twenty-four hours in 60% ethyl alcohol. The fiber was then removed and slowly elongated 38% while drying. The dry fiber was strong, pliable, showed good molecular orientation, and was remarkably crystalline (Fig. 1). The layer line spacings on the X-ray photograph can be measured readily. From these (1) W.
E.Brier and C. W. Wilson. Ind. Eng. Cham.. 88,287 (1941).
884
COMMUNICATIONS TO TAB EDITOR I
Vol. 67
Furan-3,4-dicarhoxyk a d d was prepared according t o the literature.z Treatment of the diacid with phosphorus pentachloride in benzene readily gave the diacid chloride in 85% yield. This crystallized from benzene in colorless needles (m. p. 76"; calcd. for COHtOaCb: C1, 36.7. Found: C1, 36.5). Hydrolysis of this acid chloride give a diacid which did not depress the melting point of authentic furan-3,4-dicarboxylic acid. Heating with methyl alcohol gave a dimethyl ester identical with that prepared from the diacid and diazomethane. Concentrated ammonium hydroxide immediately gave the corresponding diamide (m. p. 262' N, 18.18. Found: [dec.]; calcd. for COHOO~NZ: N, 18.30). It is interesting to note that the success of this method of preparation of the 3,4diamide is in striking contrast to the great diffiFig. 1.-X-Ray diffraction photograph of asodium pecculty experienced in attempting to make some late fiber: CuKa radiation; fiber axis vertical; camera similar compounds from the dicarboxylic esters.**' distance 5.0 em. Reaction of the diacid chloride with sodium values the identity period in the fiber direction azide in cold aqueous acetone gave the correcan be determined to be approximately 13.1 A. sponding diazide in almost quantitative yield. This value lies between the maximum value This compound is stable when moist, but ex(10.4 A.), observed when there are two pyranose plodes on rubbing when dry. Heating the diazide rings in the identity period, as in cellulose and with ethyl alcohol gave the desired 3,4-diaminochitin, and the value (15.2 A,) observed for cer- carbethoxyfuran (I) in good yield. It formed tain cellulose derivatives' when there are three small, colorless crystals from ligroin, m. p. 166167" (calcd. for Cl~Hl,OUN1: N, 11.6. Found: pyranose rings in the identity period. The symmetry of the galactnronide chain in N, 11.4).6 It is of interest that the Corresponding reaction pectin evidently approximates that of a threefold screw axis but with the angle between the plane in the benzene series gives not the diaminoof the pyranose rings and the fiber axis somewhat carbethoxy compound, but (11), the cyclized larger than occurs in cellulose and its derivatives. benzimidazole derivative.' This is another exThe threefold screw axis is also suggested by the ample of the difficulty of fusing a five-membered fact that the sodium pectate fiber diagram can be ring in the 3,4-position of a furan nucleus. indexed on a hexagonal lattice. The true unit cell COOGHr COOGH, can only he pseudohexagonal, however, for reasons that will be discussed elsewhere. A detailed analysis of the fiber diagram will he published in the near future. (2) J. Gundermso. & 9hyrik. C k m . , l l B , 887 (IBST).
RESEARCH L~ORAIORY BUREAUOF AGRICULTURALAND INDUSTFSALCHEMISTRY A c n i c u L m RESEARCHADMINISTRATION U. S. DEPARTMENT OF ACRICUI.TURF. K.J. PALMER The work reported in this Communication had ALHASY 6. CALIPORSIA H L O t z m R to be discontinued almost two years ago. RECEIVED A p R n 16. 1945 DEPARTMENT OF CHBMISTRY
WESTERN REGIONAL
IlNlVERSlTY OF Wl?CONSIN
THE SYNTHESIS OF 3 CDIAMXNOCARBETEOXYF&AN
Sir: The recent interest in 3,4diaminocarbethoxyfurans' prompts us to record a synthesis of the parent compound of this series (I). (1) Hofmnno. Tms JOURNAL. 61, 694 (1845).
MADEQN.WISCONSIN G i t m x t STORK RECEIVEDAPRIL 12. 1945 (2) Reiehstein. Gnlssntr. Sehindlcr and Hnrdmeier. Heir. Chiw. A l o . 1%276 (1833). (3) W e . En.,5T, 1864 (1824). (4) Bilfon and Linrtead. J . Chew. Sm.. 912 (1937). ( 5 ) Analysis kindly perlormed by Paul Klefrke. ( 0 ) Lindemann and Sehultbeia. Ann.. 464, 237 (1928)
