As part of a study of the chemistry and pharmacology of urethans, a number of substituted urethans have been prepared in this Laboratory, and it seemed desirable to record those that have not previously been described in the literature, and to describe improved or modified methods of preparation for some that have been reported already.These compounds have been prepared (1) by treating a solution of an amine in ether or benzene with the required amount of alkyl chlorocarbonate in the presence of an aqueous solution of sodium or potassium hydroxide, or (2) by heating together an amino compound and an alkyl chlorocarbonate with or without a solvent, or (3) by heating together a urethan with an acid chloride with or without a solvent.Preliminary observations on the pharmacological properties of some of these compounds are included in this paper but detailed studies will be reported elsewhere.

Vol. 49 diluted with 60 cc. of water and distilled until the temperature of the mixture reached about 98". acidified with concd. hydrochloric acid, using Congo Red paper as an indicator. The malonic acid was separated and the aqueous liquors were extracted with ether. The separated malonic acid was also dissolved in the ether, the ether solutions mixed and dried with calcium chloride and then the ether evaporated. The residue was heated in a round-bottomed flask with an air-cooled reflux condenser for two hours at 160-168". The residue was distilled under diminished pressure and the yields of the five monobasic acids from n-amyl to n-nonyl were, respectively, 70, 51, 55, 61 and 72% of the calculated amount. TABLE 111 A . 2 -C~~~~~~~~~~~~ ALKYL ACETIC ACIDS The residue was refluxed for two hours. It was then cooled to 1 0 ' and , Carbon, % Hydrogen, % Acids B. p.. "C. ' E d: Calcd. Found Calcd. Found CsHiCH(n-CaH11)COzH 142-145 (5 mm.) 1.4659 0.9629 73.39 73.41 10.27 10.59 C S H I C H ( % -C~H~) COzH 150-155 (5 mm.) 1.4671 .9573 74.21 73.88 10.56 10.73 C S H~C H (~-C~H I S ) COzH 162-165 (4 mm.) 1.4683 ,9499 74.93 75.18 10.78 11.05 CsHiCH(n-CsHlt) COzH 170-173 (4 mm.) 1.4687 .9452 75.58 76.19 10.99 11.43 CsHCH(n-CaH1a)COzH 173-176 (3 mm.) 1.4690 ,9436 75.80 76.10 11.13 11.12 Summary 1. 2. A2-Cyclopentenyl alkyl acetic acids where the alkyl varies fromThe bactericidal action toward B. Lefirae has been shown to inn-amyl to n-nonyl have been prepared.crease rapidly with increase in molecular weight of the alkyl group. URBANA, ILLINOISIn a study of guanidine derivatives, Nencki2 observed that dicarbethoxyguanidine was decomposed by alcoholic ammonia at 100' into monocarbethoxyguanidine and urethan. Malonyldi-urethan was found by Conrad and Schulzea to be decomposed by the same reagent into malonamide, ammonium barbiturate and urethan. In neither of these reactions was a urethan grouping converted into a urea as might have been expected. The products obtained by Conrad and Schulze show that from some molecules of diurethan both urethan groups were removed, while from others only one was removed, and the carbethoxymalonamide so formed then condensed to barbituric acid.The action of ammonia and amines on carbonyldi-urethan has been 1 A preliminary version of this paper was received