METHOD OF PRODUCING 1-ADAMANTANE CARBOXYLIC ACID Russian patent published in 2011 - IPC C07C61/135 C07C51/97 C07C51/43 C07C51/42 

FIELD: chemistry.

SUBSTANCE: invention relates to pharmaceutical chemistry, specifically to a method of producing 1-adamantane carboxylic acid which is a basic intermediate product in production of antiviral agent ramantadin. The method of producing 1-adamantane carboxylic acid is realised through carboxylation of 1-nitroxyadamantane with methanoic acid in the presence of sulphuric acid. 1-nitroxyadamantane is dissolved in 93.0-96.0% sulphuric acid containing 0.7-1.0 moles of urea. Methanoic acid or its salt is added in amount of 1.5-2.0 mol per mole of 1-nitroxyadamantane and held at temperature 18-20°C for 4-24 hours. The reaction mass is diluted with water at temperature 90-95°C and held at temperature 80-90°C for 30-40 minutes to complete hydrolysis of the formed 1-nitrourea and 1,3-dinitrourea. Adamantane carboxylic acid is the cooled and filtered. Output of the end product with melting point of 177-180°C is theoretically equal to 90-99%.

EFFECT: design of an efficient method of obtaining 1-adamantane carboxylic acid.

3 cl, 8 ex