Ralph Breitenbach

Synthesis of tigogenyl β-O-cellobioside heptaacetate and glycoside tetraacetate via Schmidt's trichloroacetimidate method; some new observatons.

Abstract In studying the synthesis of tigogenyl β-O-cellobioside 1 via the trichloroacetimidate method of Schmidt, cesium carbonate was found to be an efficient reagent for the synthesis of peracetylated disacchadde α-trichloroacetimidates. Zinc bromide was superior to BF 3 ·Et 2 O for coupling these disaccharide α-trichloroacetimidates with the steroid tigogenin.

A PRACTICAL SYNTHESIS OF 3(S)-METHYL-HEPTANOIC ACID FROM (S)-CITRONELLOL

Abstract Chiral 3-methyl-heptanoic acid is readily accessible by functional group manipulation of optically active citronellol. In principle, this approach is general and could be applied to the synthesis of chiral 3-methyl-alkanoic acids seven carbon atoms in length and longer.

Synthesis of an optically active octahydro-2H-pyrido[1,2-a]pyrazine based CNS agent

Abstract A synthesis of an optically active octahydro-2H-pyrido[1,2-a]pyrazine is presented. The key sequence involved the equilibration of an optically active cis-aldehyde to give the thermodynamic trans-aldehyde that was trapped by nitromethane anion.

An Efficient Synthesis Of 6-Substituted 2-(2H-[1,2,4]Triazol-3-Ylmethyl)-1,2,3,4-Tetrahydro-Isoquinolines

Abstract A synthesis of 6-nitro and 6-amino 2-(2H-[1,2,4]triazol-3-ylmethyl)-1,2,3,4-tetrahydro-isoquinolines using a bis-alkylation process is described. 5-(Aminomethyl)-1-(p-methoxybenzyl)-triazole was prepared by a regioselective route from 1,2,4-triazole.

A Novel Synthesis of the Antipsychotic Agent Ziprasidone

Abstract A new synthesis of the antipsychotic ziprasidone from 2,5-dichloro-4-nitrotoluene 3 is presented. The nitro group in 3 was used to activate the ortho-chlorine for displacement and the methyl group for enamine formation and introduction of the piperazinyl moiety.

A Novel Synthesis of 3-Amido-5-phenyl-benzazepin-2-one via an Intramolecular Amidoalkylation

Abstract A synthesis of N-(8-Methyl-2-oxo-5-phenyl-2,3-dihydro-1H-benz[b]azepin-3-yl)-benzamide 2 via an intramolecular amidoalkylation is described.