3154
VOl. 77
SOTES
tioii was filtered off, and the filtrate lyophilized. Approximately 20 g. of a n amorphous hygroscopic product was obtained. The product was added t o 100 ml. of glacial acetic acid, heated to 95" and kept warm until crystalline. After cooling t o room temperature, the product (18 g . ) was filtered off and was washed several times with ether. The compound was recrystallized as bundles of microscopic needles from approximately 50 times its weight of hot glacial acetic acid. The compound is assumed to be the acetic acid salt of S-cysteinosuccinic acid. '4nal. Calcd. for CgH,:NOsS: C, 36.47; H , 5.05; S, 4.88; S, 10.78. Found: C, 35.90; H , 5.10; X, 4.85; S, 10.77. ilfter drying over CaClp and KOH for two weeks, the total acid equivalency of a sample based on a mol. wt. of 297 was 2.88 (theory 3.0), equivalents volatile acid 0.85 (theory 1.0), u i d equivalents non-volatile acid (calculated) was 2.03 (theory, 2.00). Lpon heating the crystals became moist at 118 to 120'; they contract from 120 to 124", and then swell until they decompose with bubbling a t 132 to 134". The compound is very soluble in ethanol and water but only slightly soluble in ether. I t gives a negative -SH or -S-Sspot test but a positive test for thioether5and a positive ninhydrin test for amino acids. Although the addition of sterile fumaric acid to agar niedia containing cysteine stimulates growth of small inocula of the yeast phase of Histoplusma capsulatzim on agar media,6 the addition of the S-cysteinosuccinic acid salt instead of fumaric acid has no effect. I n liquid media the compound does not substitute for the cysteine requirement.
Acknowledgment.--Appreciation is expressed for the helpful suggestions given by Dr. Evan C. Horning for the isolation and identification of the fumarate-cysteine addition compound. ( 3 ) G. Toennies and J. J. Kolb, Anal. C h e m , 23, 81'3 (1951) (6) L. Pine, unpublished results.
1,ABORATORY OF I&-FECTIOUS NA~IONAL MICROBIOLOGICAL I NAlIONAL INSTITUTES O F HEALTH BETIIESDA, MD.
crystallized from 20 nil. of n-butyl alcohol dnd after filtration the crystals were washed with a small amount of ether. All of the derivatives crystallized in the form of fine white needles with the exception of the two noted in Table I. ill1 melting point5 are corrected.
THIOESTERS O F
Rlercdptan used
B Y DAVIDC. O'DOSNELL,HENRYA. MARIAXIAND DENS J . DOWSISG~ RECEIVEDFEBRUARY 2, 1935
lye have reported p r e v i o u ~ l ythe ~ ~ use ~ of 3,-1,.5triiodobenzoyl chloride for the identification of cellosolves, carbitols and alcohols. The increasing use of mercaptans has prompted us to extend the use of this acid chloride to the identification of these compounds. The acid chloride was prepared by the method previously d e ~ c r i b e d . ~All of the mercaptans were obtained commercially. Experimental IVith all but t w o of the mercaptans, 1 nil. of the mercaptan was added t o 1 g. of the acid chloride in a 15-cm. test-tube and gently heated with a micro-burner for 10 minutes. Methyl and isopropyl mercaptans, because of their low boiling points, were treated differently. I n these two cases 1 g. of the acid chloride was dissolved in 50 ml. of ether, 1 g. of the mercaptan added and the solution was allowed t o stand far 10 minutes. It was then heated for 5 minutes, the ether cvaporated and the residue crystallized from a solvent. 'The lower molecular weight thioesters were crystallized from 10 ml. of either methyl or ethyl alcohol. T h e higher molecular weight aliphatic and the aromatic thioesters were -
~~
~-
( 1 ) 'Taken from theses submitted in partial fulfillment for t h e
M.S.
degree. ( 2 ) V O'Donnell and R . Carey, THISJ O U R N A L , 68, 1865 (1946) l:O I ) O'DonneIl, J. K e l l e y , R . O'hlalley and R. IJpham, ihicl., 7 0 , U!l48), ( 1 ) C . Rlrtnirir iind I . ITitntrr. .l. O r q .
lt;ii
< Iipiri,,
6, .iOX (IO4I)).
Yield, SI p , ' C
yo
Formula
Iodine, '6 Calcd Found
71.56 133.6-154.6" 43 M e thy1 68.38 37 n-Propyl 97.8-98.8" 68.40 28 15opropyl 133 ,4-15*5" 66.96 48 n-Butyl 90-91.4" 37 66.30 Isobutyl 89.5-90.8" 64.63 83 .2-84.4"' :3 4 n-Amyl 63.63 n-Hexyl 64.3-6.5 .2" 49 62.13 11 7n-70. sb n-Heptyl 60.50 46 n-Octyl 67-68.2'' 59 . 0:1 71)-70.8" 64 n- Sonyl _58.119 *>,I 76-77. 2h u-Decyl 57,118 78.6-79.8" 62 ti-Undecyl 53.20 7 5 .4-78.8' 33 tz-Dodecyl n-Tetra53,iti 86 4-87 43Y decyl 51.65 91 0-91 8" 62 Hexadecyl o-Thio30 CliHgOSI3 62.83 6 2 . 4 4 cresol 9s.4-99 , 0" 116,2-117 . 0' 60 CiiHgOSI3 62.83 6 2 . 8 8 Benzyl &Phenyl61.62 63 ethyl ru-Phenyl59.83 t5$) propyl b Ethyl alcohol as solvent. ( 8 hIethX1 alcohol a s solvciit. v-Rut!-l 'ilcohol :ii solvelit. White plates. e White gr:tnules. I 1E P A K T 11E A , I
3,4,5-Triiodobenzoyl Chloride as a Reagent for Identifying Mercaptans
TABLE I ~,~,~-TRIIODOBEN ACID ZOIC
(1 F
C I I E M I ~Y ~ R
Bos r o s C I)LI.EGE CHESTSTTHILI., 67,~ Z A S S .
Preparation of Pure 2-Aminonitropyridines and 2-Aminonitropicolines. Rapid Separations by Sublimation B Y LEWIS9. PINOASD ITINFIELD S. ZEHRCSGIIlI IZECEIVED DECEMBER 16, 1934
Considerable information exists on the nitratioii of 2-aminopyridine and the 2-aminopicolines. However, there is reported no simple, rapid method of separating the isomeric nitroamines of the pyridine series. This paper gives the results of a study of sublimation as a means of rapid, clean separation. Separation of aminonitropyridine has been xcomplished by steam distillation and fractional crystalli~ation.~*~b,3 I n some instances, no attempt a t separation was made until the mixture of isomers had completed a series of additional reactions after which one modified isomer was recovered and the other l ~ s t . ~ , ~ Separation by sublimation seemed feasible since a vicinal nitroamine is capable of chelation with a resulting increase in molecular symmetry and vapor (1) From a thesis submitted t u t h e faculty of Allegheny College in partial fulfillment of t h e requirements for the M.S. degree, June, 1954. (2) (a) A . B. Chichibabin and B. A. Razorenov, J. Russ. P h y s . Chetn. Soc., 47, 128fi (1915); .I. Cheiu. S O C . , 108, I , 992 (1915); ( b ) T C ~ ~ I I I Wa nI lIi I C c r . o r x L r d d TRIS J O I J R X A I . . 6 4 , 1 6 ~ i31 ~ 1 2 ) . G31 \ I \ l'liilli~i~. ./ i'iri, 'IC), , I:? ~ 1 ~ l L l ) .
w.
