4-Toluenesulfonyl chloride → HCID 13799189, compound

Participants

Reaction Conditions

Reaction Steps

3.9 g of 5-benzyloxy-4-methoxymethyl-beta-carboline-3-carboxylic acid ethyl ester is dissolved in 70 ml of dichloromethane with 1.84 ml of triethylamine and 0.54 g of dimethylaminopyridine. The solution is cooled to 0° C. and then mixed by portions with 2.54 g of tosyl chloride. After stirring for 2 hours at room temperature and standing overnight, it is shaken out three times with sodium hydrogen carbonate solution, the organic phase is concentrated and recrystallized from acetic acid. 4 g of 5-benzyloxy-4-methoxymethyl-9-tosyl-beta-carboline-3-carboxylic acid ethyl ester with a melting point of 149°-150° C. is obtained. This 4 g is dissolved in 40 ml of tetrahydrofuran under argon and mixed at room temperature with 17 ml of a 1.7 molar solution of calcium diisopropoxy aluminum hydride in tetrahydrofuran (Capal); after refluxing for one hour, 17 ml of Capal is added once more and refluxing is continued for 2 hours. After cooling, it is mixed with 2N sodium hydroxide solution and shaken out with acetic acid. The organic phase is concentrated and 3.1 g of 5-benzyloxy-4-methoxymethyl-9-tosyl-3-hydroxymethyl-beta-carboline is obtained, which is suspended in 57 ml of toluene and mixed with 1 ml of azodicarboxylic acid ester. After refluxing for 12 hours, it is concentrated and chromatographed over silica gel with cyclohexane:acetic acid=1:1 as eluant, 1.8 g of 5-benzyloxy-4-methoxymethyl-9-tosyl-beta-carboline-3-carbaldehyde with a melting point of 125°-127° C. is obtained.

Provenance & Evidence