COMMUNICATIONS TO THE EDITOR
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additional experiments has enabled us to decide between the two views. Only two of the unpacked series need be quoted here, Viz., J1 and Jl2.
formyl chloride in the reaction mixtures was too small to be of importance in accounting for the discrepancy between theoretical and observed pressure change. It was not our intention in J1, T 140’. J l 2 , T 150”. HCHO 197.4mm.; Clz 99.5 mm. HCHO 378.0 mm.; Cla 53.0 mm. the previous Note [THIS JOURNAL, 57, 590 1, min. p , mm. 1, min. p . mm. (1935)] to account for the total discrepancy in this 0 296.9 0 431.0 manner but only to account for what was left 12 365.9 8 441.0 20 376.8 17 442.0 after correcting for the normal amount of polym60 376.7 27 438.5 erization. The data from experiment K5 in A p max. 79.9 mm. A 9 max. 11.0mm. Found: CO 9 3 . 9 mm. Found: CO 52.1 mm. the packed reaction vessel (a condition very unHCHO polym.. - 14.0 polym. 41.1 - -= 0.149. HCHO 0.789. favorable for the existence of formyl chloride) HCHO reacted 93.9 H C H O reacted 52.1 seem to be in favor of the higher rate of polymeriThese experiments show how the discrepancy zation in the presence of chlorine, suggested by between the theoretical and the observed pressure Spence and Wild. The failure of the HCI/CO change increases with the formaldehyde-chlorine ratio to deviate appreciably from two also supratio. According to Krauskopf and Rollefson’s ports this view. view, 40 mm. of formyl chloride must have been DEPARTMENT OF CHEMISTRY K. B. KRAUSKOPP UNIVERSITY OF CALIFORNIA G. K. ROLLEFSON produced in 512 after eight minutes, remained BERKELEY, CALIFORNIA unchanged a t 150” for a further nineteen minutes, RECEIVED MAY 16, 1935 and must thrn have been completely decomposed in the process of pumping out over liquid air. However, experiments in a vessel packed with powdered glass gave similar results: e. g., K5 ORIENTATION IN THE FURAN SERIES. HILL’S 3,5-DIBROMO-2-FUROIC ACID (HCHO 206.0 mm.; Cl, 168.8 mm.). 15.4 mm. Sir: of formaldehyde polymerized in forty-eight minThe pivotally significant “3,5-dibromo-2-furoic utes before a.ddition of the chlorine, while polyacid” [Hill and Sanger, Proc. Am. Acad. Arts. Sci., merization during forty-eight minutes of reaction 21, 135 (1885)] is actually 4,5-dibromo-2-furoic amounted to 27.5 mm. Any formyl chloride acid. This has been demonstrated as follows: present in this case would scarcely decompose a t (1) The /3-bromo-2-furoic acid, obtained by rethe cooler surface of the tubing leading to the placing an a-bromine in the dibromofuroic acid liquid air trap, and once frozen out, the carbon by hydrogen, gives 2,4-furandicarboxylic acid on monoxide would be lost to the analysis, resulting hydrolysis of the nitrilo-acid secured by heating in an increase in the HCI/CO ratio. However, with potassium cyanide and cuprous cyanide our ratios always remained very close to two, and the discrepancy between the amount of reaction [Rosenmund and Struck, Ber., 52B, 1749 (1919)l. and the pressure change must be attributed to an (2) The dibromofuran, obtained from decarboxylainduced polymerization of the formaldehyde. tion of the dibromofuroic acid, gives (by a correNevertheless, as we had already pointed out sponding treatment) 2,3-furandicarboxylic acid. [J. Soc. Chern. I d , 54, 83 (1935)l in agreement (3) The ethyl ester of the dibromofuroic acid with Krauskopf and Rollefson, it is probable gives with phenylmagnesium bromide the bromothat formyl chloride occurs as an intermediate in ==C(C&)z, which with 5% the thermal reaction, but in our opinion, its con- crotolactone, O= 0 centration must be small. THEUNIVERSITY R. SPENCE sodium hydroxide yields a,a-diphenylacetone. LEEDS,ENGLAND W. WILD By a series of inter-relating reactions it now RECEIVED APRIL29, 1935 appears that Hill’s structures for 3-sdfo-5-bromo2-furoic acid, 3-sulfo-5-chloro-2-furoic,and 3,sdichloro-2-furoic acid warrant revision. THE REACTION BETWEEN CHLORINE AND =-E
BroH
FORMALDEHYDE
Sir: The experiments described in the note of Spence and Wild indicate that the amount of
CONTRIBUTION FROM THE HENRYGILMAN CHEMICAL LABORATORY OF ROBERT J. VANDER WAL IOWA STATECOLLEGE RAYMOND A. FRANZ AMES,IOWA ELLISV. BROWN RECEIVED MAY6,1935
