Bridged-ring nitrogen compounds. Part 7. Synthesis of the 1,4-ethano-3-benzazepine ring system

Synthesis of Functionalized Bicyclo[3.2.1]octanes and Their Multiple Uses in Organic Chemistry

“…A representative example of this mode of carbocyclization is the elegant one-pot construction of tricyclic diketone 114 , through 113 , by a tandem intramolecular acylation/Claisen ring closure observed by reaction of acid 112 with polyphosphoric acid (PPA) …”

Novel Mast Cell-Stabilising Amine Derivatives of 3,4-Dihydronaphthalen-1(2H)-one and 6,7,8,9-Tetrahydro-5H-benzo[7]annulen-5-one

“…Expansion of the hydroaromatic tetralone ring to that of a benzosuberyl moiety was the next synthetic target. Compared to 4-bromotetralone, the benzylic monobromide 6 of benzosuberone [18] is a more stable molecule, so much so that nucleophilic substitution with cyclopentylamine proceeded slowly and was not a clean transformation, producing considerable quantities of imine 7. Acidic hydrolysis of the imine followed by methylation afforded 10, as shown in Scheme 1.…”

Synthesis and reactions of 2,3,5,6-tetrahydro-2,5-ethano-3-benzazocin-4(1H)-one and a thieno-extended analogue: X-ray structure of 3-methyl-2,3,5,6-tetrahydro-2,5-ethano[1]benzothieno[3,2-d]azocin-4(1H)-one

“…Treatment of the mixture of N-methylated lactams (16) and (20) with phosphorus pentasulphide gave a mixture (67%) of the corresponding N-methylated thiolactams (18) and ( 22), respectively, also inseparable by TLC or column chromatography. Again HPLC allowed separation both qualitatively and quantitatively; in this case isomer (18) was eluted first with isomer (22) following using n-hexane-ethyl acetate (7 : 3) as eluant. The ratio (45 : 55) of isomers corresponded favourably with the ratio of N-methylated lactam starting materials.…”

“…These compounds were separated by HPLC both qualitatively and quantitatively using n-hexane-ethyl acetate (7 : 3). Compound (18) was eluted first, m.p. 147-148 "C, followed by compound (3 H, m, ArH) (Found: C, 68.7; H, 5.7; N, 81.5%; M ' , 227.…”