Synthesis of S 9490-3 [U-14C-cyclohexyl] 1-{[(2S)2-[(1S) 1-carbethoxybutyl amino] 1-oxopropyl}(2S,3aS,7aS) perhydroindole-2-carboxylic acid terbutylamine salt 1 and S 9780 [U-14C-cyclohexyl]1-{[(2S) 2-[(1S)1-carbethoxybutyl amino]1-oxopropyl} (2S, 3aS, 7aS) perhydroindole-2-carboxylic acid and of [3,4-3H-butylamino] S 9490-3 and [(3,4-3H-)butylamino] S9780, potent inhibitors of angiotensin converting enzyme at very high specific radioactivities

The syntheses of S 9490-3 [U-14C-cyclohexyl] 1-brace[(25) 2- [(1S) 1 - carbethoxybutyl)amino] 1-oxopropylbrace (25, 3aS, 7aS) perhydroindole-2-carboxylic acid terbutylamine salt and S 9780 [U-14C-cyclohexyl]1- brace[(25) 2 - [ (1S)1-carbethoxybutyl) amino]1-oxopropylbrace (2s, 3aS, 7aS) perhydroindole-2-carboxylic acid and of {3,4-3H-butylaminol] S 9490-3 and [(3,4-3H-)butylaminol] S 9780, potent inhibitors of angiotensin converting enzyme are described. Very high specific activity compounds were obtained. (author)