Organophosphorus compounds. XI. Synthesis of some 1,2,3,4,5,6-Hexahydro-1,5-methano-4,1-benzazaphosphocines

Abstract

1-Hydroxy-1,2,3,4-tetrahydrophosphinoline 1-oxide (2a) was converted via the corresponding acid chloride (2b) into the 1-vinylphosphine oxide (3) which underwent a Michael-like addition with dimethylamine to give 1-(2'-dimethylaminoethyl)-1,2,3,4-tetrahydrophosphinoline 1-oxide (6). The successive reduction of (6) with trichlorosilane, and oxidation with sulphur afforded the phosphine sulphide (7). The reaction of 1-vinyl-1,2,3,4-tetrahydrophosphinoline 1-oxide (3) with N-bromosuccinimide followed by treatment with dimethylformamide gave 1-vinyl-1,2-dihydrophosphinoline 1-oxide which, under mild conditions, underwent Michael-like addition of amines to the vinyl group to give, for example, 1-(2'-propylaminoethy1)-1,2-dihydrophosphinoline 1-oxide. When heated in a sealed tube at 140-150° in water for 60 h this amine was converted into 4-propyl-1,2,3,4,5,6-hexa- hydro-1,5-methano-4,1-benzazaphosphocine 1-oxide. Several related tricyclic compounds including the corresponding phosphines and phosphine sulphides were synthesized. Several of the new aminophosphorus compounds were tested for analgesic activity.