Potassium Hydroxide → p-(2-Thenoyl)hydratropohydroxamic acid

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Reaction Steps

To a stirred solution of 12.6 parts of ethyl p-(2-thenoyl)hydratropate in 35 parts of methanol is added successively and while cooling, first a solution of 6.05 parts of hydroxyl amine hydrochloride in 35 parts of methanol and then a solution of 7.3 parts of potassium hydroxide in 35 parts of methanol. Upon completion, the whole is stirred for 30 minutes. The mixture is filtered and the filtrate is stirred for 3 days at room temperature. The reaction mixture is evaporated and the residue is taken up in water. The aqueous solution is acidified with hydrochloric acid solution and the product is extracted with ether. The extract is washed with water, dried, filtered and evaporated. The residue is taken up in water, alkalized with sodium hydroxide solution, washed with ether and the aqueous phase is acidified with concentrated hydrochloric acid solution. The product is extracted with ether. The latter is washed with water, dried, filtered and evaporated. The residue is purified by column-chromatography over silicagel, using a mixture of chloroform and 10% of methanol as eluent. The pure fractions are collected and the eluent is evaporated. The residue is triturated in a mixture of petroleumether and diisopropylether. The solid product is filtered off and crystallized from 2-propanol, yielding p-(2-thenoyl)hydratropohydroxamic acid; mp. 143.5° C.

Provenance & Evidence