A. D. Ward

Synthesis and substitution reactions of N-protected 2-(phenylselenonylmethyl) pyrrolidines

Alkyl phenyl selenides derived from the benzeneselenenyl chloride induced cyclization of N-protected pent-4-enylamines can be converted in good yield into the corresponding 2-hydroxymethyl- or 2- alkoxymethyl-substituted pyrrolidines by oxidation to the corresponding selenone, followed by reaction with water (or hydroxide) or with the corresponding alcohol. Details of the reactions and possible mechanisms for the substitution are discussed.

The Reactions of N-Substituted 2-(Dimethylallyl)aniline Compounds with Phenylselanyl Halides

Cyclization of the carbamate of 2-(dimethylallyl)aniline with phenylselanyl chloride (benzeneselenenyl chloride) gave a 1 : 1 mixture of a dihydroindole and a tetrahydroquinoline. With phenylselanyl bromide only the dihydroindole was obtained. Addition of methanol to the silica used in the procedure trapped the reaction at the non-cyclized stage forming a 3-methoxy-3-methyl-2-(phenylselanyl)butyl side chain. The sulfonamide of 2- (dimethylallyl)aniline only formed the dihydroindole with phenylselanyl chloride. The corresponding trifluoroacetamide derivative did not form any cyclized product under the same conditions. The dihydroindole could be converted into the corresponding alkene by oxidative removal of the phenylseleno group. 4-Ethoxycarbonyl-2-(3,3-dimethylallyl)aniline cyclized with mercuric nitrate to give, after a reductive workup, a 2,2-dimethyltetrahydroquinoline. The X-ray crystal structures of ethyl N-{2-[3-methoxy-3-methyl-2- (phenylselanyl)butyl]phenyl}carbamate and 2-[1-methyl-1-(phenylselanyl)ethyl]-1-[(4-methylphenyl)sulfonyl]-indoline are reported.

Crystal structure of 1,7-{bis[6-methoxy-8-(4-toluenesulfonamido)quinol- 2-yl]}-heptane, C41H44N4O6S2

C 41 H 44 N 4 O 6 S 2 , monoclinic, P12 1 /c1 (no. 14), a = 17.241(2) A, b = 12.291(2) A, c = 19.578(6) A, β = 111.03(2)°, V= 3872.5 A 3 , Z=4, R gt (F) = 0.046, wR ref (F 2 ) = 0.152, T= 173 K.

4-[(4-Methoxy­benzyl)­sulfanyl]­benz­aldehyde

The title compound, C15H14O2S, adopts an extended conformation that enables the formation of π⋯π and C—H⋯O contacts in the crystal structure, leading to the formation of columns.