GB568512A - Formylacetic ester - Google Patents

Abstract

Alkali metal formyl acetic esters are prepared by reacting an aliphatic alcoholic ester of acetic acid, such as ethyl acetate, with an aliphatic alcoholic formate, such as methyl formate, and an alkali metal alcoholate such as sodium methylate, and introducing carbon monoxide under pressure. The reaction may be carried out at elevated temperatures and in the presence of a solvent such as methanol. The resulting sodium formyl acetic ester may be reacted with a guanidine salt, for example guanidine nitrate, without being first isolated, to yield isocytosine. In an example, sodium methylate, ethyl acetate and methyl formate are heated with carbon monoxide under pressure. The reaction product containing sodium formylacetic ester is treated with guanidine nitrate and caustic soda to yield sodium isocytosine which on treatment with acid gives isocytosine. Potassium alcoholate, methyl, isopropyl or butyl acetate and ethyl or isopropyl formate may be used similarly. The Specification as open to inspection under Section 91 describes in a further example the preparation of the formyl acetic ester by reacting sodium methylate in methanol and ethyl acetate with carbon monoxide under pressure; the product is condensed with guanidine nitrate as above. This subject-matter does not appear in the Specification as accepted.