Synthesis and anti-arthritic activity of a series of 1-aryl-3-dimethylamino-1,4-dihydroisoquinolines

1-Aryl-3-dimethylamino-1,4-dihydroisoquinoline (1) were synthesised from 1-aryl-1,4-dihydroisoquinol-3-ones (2) by heating in dimethylcarbamyl chloride. Compounds bearing electron withdrawing substituents on the 1-aryl ring were active in inhibiting polyarthritis in the rat adjuvant arthritis model, when administered orally. Several compounds were also potent inhibitors of inflammatory cell accumulation. The most potent compound of the series, overall, was the 3′-chloro analogue, 10.