NOTES
3696
VOL.27
crystallized after having been allowed to stand for 1 day. The crystalline mass was freed of oil by pressing it on a clay Dimethyl S-Cyan0-3,4-pyrazoledicarboxylate (11).-Diplate. The light yellow crystals (8.14 g., 40%) were remethyl acetylenedicarboxylate (40 g., 0.282 mole) was crystallized from water and gave colorless needles, m.p. (approximately 101'. added to a solution of diaz~acetonitrile~ 20-25 g., 0.3-0.37 mole) in 3.5 1. of ether and the mixture A n a l . Calcd. for C&N4O2.H2O: C, 46.14; H, 3.87; allowed to stand overnight. Evaporation of the solvent N, 26.91. Found: C, 45.86; H , 4.28; N, 26.76. left a crystalline residue which was pressed dry on a porous If the crystals were kept in a desiccator they liquified. clay plate (45 g., 76.3%). In several runs the yield varied Exposure to air, however, or recrystallization from water slightly (72-90yo) because of the somewhat erratic results again gave the original compound. in the preparation of the diazoacetonitrile solution. DiThe infrared spectrum exhibited characteristic bands a t aioacetonitrilr Bas always alloued to react in dry ethereal 2.89 p , 4.52 p, 5.82 p . solution because it was inconvenient to isolate large quantiThe compound was soluble in benzene, ether, alcohol, ties of the rather explosive compound. Recrystallization and acetonitrile. from an ether-petroleum ether mixture vielded white crys3,4-Dicyano-5-carbamoylpyrazole (V).-E thy1 3,4-ditals, m.p. 102-io3.50. cyano-5-pyrazolecarboxylate (2.2 g., 0.0107 mole) was disA n a l . Calcd. for CgHiX,04: C, 45.94; H , 3.38; N, solved in a mixture of 10 ml. of concentrated aqueous 20.09. Found: C, 45.87; H , 3.30; T , 20.34. ammonia and 1 ml. of methanol and allowed to stand for Ammonium Salt of 3,4-Dicarbarnoyl-5-cyanopyrazole 12 hr. Evaporation of the mixture to dryness gave a solid (111).-A mixture of dimethyl 5-cyanopyrazole-3,4-di- residue (1.67 g., 96%) which was dissolved in hot ethanol carboxylate (2 g., 0.096 mole) and concentrated aqueous and reprecipitated with ether. The compound became yellow ammonia was heated in a sealed tube in a steam bath for a t 200" but did not melt. 2 hr. The light yellow mass (1.3 g., 70%) which precipiA n a l . Calcd. for C6HaTsO: K, 43.47. Found: N, tated on cooling was filtered and recrystallized from hot 43.58. The infrared spectrum exhibited characteristic water, 1ri.p. 275-280' (dec. with gas evolution). bands a t 2.96 p, 3.22 p , 4.56 p , 6.05 p . A n a l . Calcd. for C6HsToOs: pr', 42.84. Found: N, Tricyanopyrazole .-3,4-Dicyano-6-carbamoylpyrazole (1 43.02. g., 0.0062 mole) was suspended in 8 inl. of phosphorus The same compound was obtained after having allowed oxychloride and the mixture refluxed for 15 niin. Then it the diester to stand with aqueous ammonia for 4 days. was decomposed with ice and extracted with ether in a 3,4,5-Tricyanopyrazole (I).-The ammonium salt of 3,4- Soxhlet apparatus. Evaporation of the solvent gave tritlicarbamoyl-5cyanopyrazole ( 5 g., 0.026 mole) was sus- cyanopyrazole (0.73 g., 83'%), m.p. 193" (from water). pend(,d in 26 ml. of phosphorus oxychloride and the mixture Mixed melting point with the sample obtained earlier was refluxed for 1 hr. Then it was decomposed with ice not 193". The infrared spectra of both samples were identical. allowing the temperature to rise above 10-15" and extracted with ether in a Soxhlet apparatus for 0.5 hr. Evaporation Acknowledgment.-The author wishes to thank of the ether gave a crude product (3.14 g., 867@),m.p. Dr. G. R. Coraor for many helpful suggestions. 170-183'. Recrystallization from water (charcoal) yielded white needles, m.p. 193-194'. The compound is very soluble in hot water, but only slightly in cold water. A n a l . Calcd. for C~HY\T~: c, 51.53; H, 0.71; h', 48.92. The Chemistry of Neuraminic Acids. I. The Found: C, 51.50; H, 0.85; N,48.43. Ehrlich Reaction1 The infrared spectrum exhibited characteristic absorptions a t 3.10 p , 4.42 p, 6.42 p , 6.80 p , 7.78 p , 8.68 p , 9.74 p , L. R. MORGAN, JR., ANI) R.SCHUNIOR 13.22 p . The silver salt of I was prepared by adding an equimolar :rinount of silver nitratc solution to an aqueous solution of Dapui tiicenls of I'hui,iiiucoloyy und -11edicine, Loziisiana State tricyanopyraxole which had been previously ncutralized University, School of Medicine, X e w Orleans 12, Louisiana with sodium bicarbonatcx. I Z ? ~ . C:tlcd. for c6N5.ig: &, 42.1. ~oUlld: &', 42.S. N-MethyI-3,4,5-tricyanopyrazole (VI). An v t I w m \ l sidii111 f h i . procvsh of st ri(lyiiig lh(>c*hcniihtry of' t i o i l of ~liazc~rrrc~tlia~ic~ u x s anltlvil i o :I solution of tric.,v:irio1~yr:imiIv (0.7 g., 0.00.4;,I I I ~ I ~ V i) n c ~ t l i c ~(r2 0 n i l . ) u n t i l 1 1 i ( s 1it)iir:iiniiiirwid (1, Lt = 21' = H), it, wab ~ i c ~ s h a r y yt.lll e:( )I( ir prsiutcvl. 'I'hc~rc~\viis :I, rrynt ;+I line> 1)rwiliiI i t ( e * . 1 o rviiiT wtigai(b i I10 lilitirlich wirtioll 1 ) t t w w ~ i l ~ ~ v : i ~ ~ ~ ~ofr :t hi ~r isolwiit oti : i r i t l rc.c.rysi:!lliz;ilic~rl o f t l w ( q x 1 (11 = It' = 11) tiiitl p-tiimcthylarni~~o~~cuzalclci : i l l i t i r rcisitirich (0.7 g.,!)I " i , ) froiii c~t11:uicil furnish*(le:olorlvss Iiydt(I'IIAB). l'revioiisly, I (I
