35202-55-2

35202-54-1

35202-55-2

General procedure for the synthesis of (3,4-dimethoxybicyclo[4.2.0]octa-1,3,5-dien-7-yl)methanamine hydrochloride from 4,5-dimethoxy-1-cyanobenzocyclobutane: reference to EP 0 534 859 Step 1: Preparation of 3,4-dimethoxybicyclo[4.2.0]octa-1,3,5-trien-7-amine hydrochloride. To a solution of 25 g of 3,4-dimethoxybicyclo[4.2.0]octa-1,3,5-triene-7-carbonitrile dissolved in 250 ml of tetrahydrofuran (THF) at room temperature was added slowly and dropwise 312 ml of borane-THF complex solution with continuous stirring for 12 hours. Subsequently, 200 mL of ethanol was added and stirring was continued for 1 hour. 100 ml of a 3.3 N solution of ethyl ether hydrochloride was added slowly and dropwise. Eventually 27.7 g of the target product was obtained in 90% yield with a melting point of 205°C.