Selective and potent .beta.2-adrenoceptor agents within the tetrahydroisoquinoline class: effect of methyl substitution at the benzylic carbon of the 1-(3,4,5-trimethoxybenzyl) group of trimetoquinol

Abstract

A systematic series of methyl (2 and 3) and dimethyl (4) analogues of trimetoquinol (1) were synthesized and evaluated for their beta 1 (atria) and beta 2 (trachea) and adrenoceptor activities. Structural assignments for the erythro (2) and the threo (3) diastereoisomers of 1-(3,4,5-trimethoxy-alpha-methylbenzyl)-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline were based on NMR spectra of the 6,7-dibenzyl precursors 15 and 16, respectively, and on the synthetic derivatives of cis- and trans-13-methyl-2,3-bis(benzyloxy)-9,10,11-trimethoxytetrahydroprotoberberine (18 and 17). The rank order of beta 2-agonist activity for these compounds was 3 greater than 1 greater than 2 greater than 4. The rank order of activity as beta 1 agonists on the guinea pig atria is 1 greater than 3 greater than 2, and 4 was inactive. The methylated analogues show selectivity for beta 2 receptors in our preliminary pharmacological studies. The threo isomer 3 is the most potent and selective beta 2 stimulant reported to date in the tetrahydroisoquinoline class.

3-Hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors. 3. 7-(3,5-Disubstituted-[1,1'-biphenyl]-2-yl)-3,5-dihydroxy-6-heptenoic acids and their lactone derivatives

“…2-(Acetoxymethyl)-4-bromo-l-fluorobenzene (9). Anhydrous sodium acetate (1.65 g, 20 mmol) was added to a solution of 8 (3.9 g, 14.6 mmol) in DMF (25 mL) and the reaction mixture was stirred under N2 on a steam bath for 11 h. The reaction mixture was cooled and distributed between H20 (200 mL) and Et^O (100 mL).…”