DE214153C - - Google Patents

Description

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IMPERIAL

PATENT OFFICE.

PATENT LETTERING

~ JVl 214153 CLASS 12 o. GROUP

Patented in the German Empire on April 28, 1908.

p-methoxysalicylaldehyde was in low yield by the action of chloroform and alkali and in Resorcinmonomethyläther by methylating with methyl iodide and potassium hydroxide resorcinaldehyde obtained (Ber d German Chem Ges Bd.:.... XIII, pp 2368 and ^2373.) · The compound is described as a very easily changeable substance, which resinates even in a vacuum when drying, which melts ^{at 62 to 63 0.}

It has now been found that when performing the methylation of resorcinol aldehyde in the absence of excess fixed alkalis, not only are far better yields of p-methoxysalicylaldehyde obtained, but that the product thus obtained is also much more uniform and only presents the really pure compound Properties differ very significantly from those described in the literature. The pure p-methoxysalicylaldehyde is a completely stable compound which does not resinify on drying, which - in contrast to the information in the literature - is not nearly insoluble in water, but rather easily soluble in heat and not at 62 to 63 ⁰ , but melts at 41 ^0. The smell of the compound is only vaguely reminiscent of vanillin, but is quite characteristic and very pleasant.

Example. 10 kg resorcinaldehyde are used in

801 of water dissolved with the addition of 15 kg of soda and the solution at 70 to 80 ° with 10 to 15 kg of dimethyl sulfate Thoroughly stirred until there is no further increase in the separating oil. After complete decomposition of the dimethyl sulfate is acidified and the resulting methoxysalicylaldehyde with steam overdone or extracted with a suitable solvent. Is one on it careful to avoid the presence of excess fixed alkali in the representation, so the execution of the method can be varied within wide limits. So it is possible, instead of dimethyl sulfate, to use halomethyl in equivalent with the same success Amount to be applied, the reaction being carried out in an open or closed vessel can be. The resorcinol aldehyde can also be dissolved in another solvent instead of in water.

The yield of pure product is very good and by far exceeds that in the Literature indicated.

Claims (1)

Patent claim: Process for the preparation of p-methoxysalicylaldehyde from resorcinaldehyde by Methylation with halomethyl or dimethyl sulfate, characterized in that the reaction is carried out in the absence of excess of fixed alkalis.