THE REACTION OF 1-ARYL AND 1-PYRIDYL-1,2,3,4-TETRAHYDROISOQUINOLIN-3-ONES WITH DIMETHYLCARBAMOYL CHLORIDE - THE PREPARATION OF AMIDINES, ISOQUINOLINES AND N-CARBAMOYLATED PRODUCTS

ogenophenyl)-1,2,3,4-tetrahydroisoquinolin-3-ones, such as 3, react wi th neat dimethylcarbamoyl chloride at 95-165 degrees C to give high yi elds of the corresponding N,N-dimethylamidines; higher temperatures fa voured N-carbamoylation. At 155 degrees C the related 1-(3-pyridyl)-1, 2,3,4-tetrahydroisoquinolin -3-ones 6-8, 10 and 11 gave lower yields o f amidine, with-those lactams not bearing an electron-releasing substi tuent on the benzo ring (6-8) giving medium to good yields of 1-(3-pyr idyl)isoquinolines. In contrast, treatment of the corresponding 1-(4-p yridyl)-1,2,3,4-tetrahydroisoquinolin-3-one 12 with neat dimethylcarba moyl chloride at temperatures between 125 degrees C and reflux gave no ne of the corresponding amidine. At high temperature the N-carbamoylat ed product 30 predominated, whereas 125 degrees C, ,N-dimethylcarbamoy loxy)-1-(4-pyridyl)isoquinoline 37 was the major product.