A compound selected from those of formula : <IMAGE> in which {TAIL ~ the meanings} of R, R1, R2 and X are as defined in the specification, and medicinal products containing the same which are in treating or in preventing {HEAD ~ a disorder} of the melatoninergic system 
A compound selected from those of formula : < IMAGE > in which { TAIL ~ the meanings } of R , R1 , R2 and X are as defined in the specification , and medicinal products containing the same which are in treating or in preventing { HEAD ~ a disorder } of the melatoninergic system
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH