Stereoselektive Synthese neuer zentral wirksamer Tricyclen vom Benzomorphan-Typ mit 2-Phenylethylamin Partialstruktur

Tricyclic CNS active agents by intramolecular Oxa-Pictet-Spengler reaction

Mitsunobu inversion of the (S)-configurated lactate (S)-7, which is prepared in four steps starting from (S)-tyrosine, leads to the (R)-configurated lactate (R)-7. The key step in the transformation of the enantiomeric lactates (S)-7 and (R)-7 into the benzomorphan analogous tricycles (R,S)-16a,b, (S,R)-16a,b, (S,S)-22, and (R,R)-22 is an intramolecular Oxa-Pictet-Spengler reaction: The amides (S)-13, (R)-13, (S)-19 and (R)-19, in which the carbonyl moiety-masked as an acetal-is linked to the 2-phenylethanol moiety, are cyclized to give the tricyclic amides (R,S)-15, (S,R)-15, (S,S)-21, and (R,R)-21, respectively. In a concentration of 100 microM both enantiomers of 16a, 16b, and 22 are not able to compete with 3H-(+)-MK 801 for the phencyclidine binding sites of NMDA receptors. In vivo, only (R,S)-16b and (S,S)-22 exhibit weak sedative and analgesic activity.

[Synthesis of homochiral 5,9-epoxybenzocyclooctenes with amino substitutents: relationship between structure and CNS activity]

This paper deals with the synthesis and psychopharmacological effects of variations of the sedative and analgesic tricyclic amines 3a and 3b: Starting with the homochiral ketone 4 the amines 5 (primary amino group in equatorial position), 7 (axially oriented dimethylamino group), 9 (additional phenyl residue in position 7), 13b, and 14b (equatorially and axially arranged dimethylaminomethyl group) and 23 and 24 (axial amino group shifted to position 9) are prepared. BBr3 cleaves the phenolic ethers of the secondary amine (+/-)-3a to yield the aminodiphenol (+/-)-10. -Keeping mice under observation for behavioral anomalies (Irwin screen) and analgesic activity (writhing test) shows, that the amines 5, 7, 9, (+/-)-10, 13b, 14b, and 23 do not reach the sedative and analgesic effects of the amines 3a and 3b, described by us.

[Synthesis and CNS-activity of spirocyclic pethidine and prodine analogs]

The bromoacetals 5a and 5b react with n-butyllithium and the piperidone 7 to yield the hydroxyacetals 8b and 8c, respectively. Cyclization of 8b and 8c followed by acid hydrolysis affords the spirocyclic hemiacetals 10b and 10c which are oxidized by PCC to give the spirocyclic prodine analogues 4b and 4c. The corresponding spirocyclic pethidine derivative 2 is prepared by alkylation of the 2-benzopyran-3-one 16 with N-Lost (17). In the mouse writhing test the spiropethidine 2 is not analgesic active up to a dose of 20 mg/kg body weight (bw). In the spirocyclic prodine series the methylated lactone 4c is the most active analgesic with an ED50-value (ED50 = 9.2 mg/kg bw) in the range of the ED50-value of tramadol.