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The Preparation of the Acetals The substitution of acetylene for acetaldehyde in the preparation of quinaldine by Nieuwland and Vogt1 led to the investigation of the possibility of a similar substitution of acetylene for acetaldehyde in the synthesis of the acetals.The process described in this paper consists in the condensation of acetylene with the alcohols into the corresponding acetals, which may be effected in the presence of a mercury salt and an acid other than the halogen acids.It is a well-known fact that acetaldehyde is produced when acetylene is passed into a dilute acid solution in the presence of a mercury salt. There is substantial proof to the effect that acetylene first forms complex intermediate compounds with water and the mercury salt with the simultaneous formation of an acid; and that the acetaldehyde is formed by the subsequent reaction between this intermediate mercury-acetylene compound and the acid produced in the first reaction. Disregarding whatever intermediate compounds are formed with the catalyst, the reaction in its simplest form may be expressed by the equation: H-C=C-+ 2H20 -*-> CH8 -CH(OH)2 -> CHS-CHO + H20. If we consider the alcohols as analogs of water, the formation of the acetals from the acetylene may be represented in a similar manner:The acetals have been prepared by the reaction of acetaldehyde on the alcohols. Since, however, dry acetylene gas reacts with anhydrous alcohols in the presence of coned, sulfuric acid and a mercury salt to form the acetals, the absence of water as such in the reaction leads us to assume that in this synthesis acetaldehyde is not formed as an intermediate compound and that acetylene functions as anhydrous acetaldehyde.The Preparation of Dimethyl Acetal.-A mixture of 500 cc. of methyl alcohol, 50 cc. of coned, sulfuric acid and 5 g. of mercuric sulfate was put into a 1 liter flask fitted with a 2-hole stopper, one hole being closed by inserting a glass rod, the other carrying a glass tube. The flask was then tared and connected with a gasometer containing acetylene over water under a pressure of about 1.5 meters of water. The acetylene was washed through coned, sulfuric acid. By removing the glass rod from the stopper the system was swept free from air. The absorption of acetylene was slow at the start, but soon increased to a very rapid rate, which was also greatly increased by shaking the flask and was accompanied by the evolution of heat. When, at intervals the absorption slackened noticeably, the glass rod was removed from the stopper to

tíllate were diluted to 15 ml., they matched 30 p. p. m. standard upon bromination. Then 30 X 13 X 25 X 50 10 X 10 X 750 7.5 p. p. m. phenol DiscussionBy the procedure as outlined, solutions containing 1 p. p. m. of phenols or even less can be analyzed in 1 hour, and the error shtiuld be distinctly less than 10 per cent. The following results are some that were obtained on synthetic solutions:In sample P. p, nt.