Notes- Synthesis of 1-Benzylnaphthalenes

Abstract

Reduction of 1-bromo-l-nitrocyclohexane (I) was then studied using an excess of zinc and ammonium bromide. In this case the only product isolated was cyclohexylamine hydrobromide (IV).When nitrocyclohexane is reduced under the same conditions cyclohexylamine hydrobromide is also formed. When, however, the reaction is stopped after only one hour, N-cyclohexylhydroxylamine (V) is formed as is reported in the literature.2•3The structure of the hydrobromide was confirmed by treatment with aqueous alkali and preparation of W-cyclohexylbenzamide (VI) from the resulting free amine. EXPERIMENTAL 1-Bromo-1-nitrocyclohexane was prepared in 60% yield according to the procedure of Iffland and Criner.4 *Melting points and boiling points are uncorrected. Analyses by Mr. E. M. Hubbard and associates and by Galbraith Laboratories, Knoxville, Tenn.Zinc reduction of 1-bromo-l-nitrocyclohexane (I), (a) To nitrocyclohexane (II). 1-Bromo-l-nitrocyclohexane (20.8 g., 0.10 mole) was mixed with 250 ml. of methanol and 17.6 g. (0.18 mole) of ammonium bromide, 11.6 g. of 90% zinc dust (0.16 mole) added and heating of the mixture begun. As in Klager's experiment, a white precipitate formed almost immediately with concomitant disappearance of the zinc dust. However, the reaction was not stopped at this point but allowed to reflux for 12 hr. further. At the end of the reaction a white solid was still present. After cooling, this solid was removed by filtration, washed with methanol, dried (Abderhalden), and analyzed.

Synthesis of Caged Nucleosides with Photoremovable Protecting Groups Linked to Intramolecular Antennae

“…The nitrobenzoic acid 21a was conveniently prepared from the known benzoic acid 22a [34], which was converted to the t-Bu ester 22b by DCC ( N,N-dicyclohexylcarbodiimide)-mediated esterification [35]. Treatment of 22b with paraformaldehyde and t-BuOK afforded the alcohol 23, which was converted to the 2-(methoxyethoxy)methyl (MEM) ether 21a in 85% yield by treatment with MEMCl in the presence of Hünig base under standard conditions [36 ± 38].…”

3,6-Bis(2H-tetrazol-5-yl)-1,2,4,5-tetrazine: A Versatile Bifunctional Building Block for the Synthesis of Linear Oligoheterocycles

“…Phenyl isocyanate, cyclohexanecarbonyl chloride ( 11j ), benzoyl chloride ( 11a ), 4‐ tert ‐butylbenzoyl chloride ( 11b ), thiophene‐2‐carbonyl chloride ( 11f ), furan‐2‐carbonyl chloride ( 11l ), acetyl chloride ( 11i ), acetic anhydride, and norborna‐2,5‐diene were purchased from Aldrich, 4‐ n ‐heptyloxybenzoyl chloride ( 11d ) from Lancaster, and were used as received. 1,4‐Bis(2 H ‐tetrazol‐5‐yl)benzene ( 4 ) (BTB),23 5‐cyanotetrazole ( 7 ),26 cyclooctyne,27 1‐methoxycyclopentene,28 4‐octylbenzoyl chloride ( 11c ),29 5‐ethyl‐ and 5‐octylthiophene‐2‐carbonyl chlorides ( 11k ) and ( 11g ),30 and N ‐methylpyrrole‐2‐carbonyl chloride ( 11m )31 were prepared according to literature procedures. 4‐Octadecylbenzoyl chloride was prepared from 4‐octadecylbenzoic acid32 by treatment with thionyl chloride.…”

“…3,6‐Bis[5‐(4‐octylphenyl)‐1,3,4‐oxadiazol‐2‐yl]‐1,2,4,5‐tetrazine (12c): Caution! Following the general procedure, BTT ( 3 ) (188 mg, 0.86 mmol) and 4‐octylbenzoyl chloride ( 11c )29 (4.00 g, 15.8 mmol) yielded, after heating at 163 °C for 60 min., cooling to room temp., collection of the precipitate by suction filtration, and washing with n ‐pentane (20 mL), 266 mg (0.45 mmol, 52%) of 12c as red plates; m.p. 182−184 °C.…”

Cross coupling reactions of organozinc iodides with solid-supported electrophiles: synthesis of 4-substituted benzoic and 3-substituted (E)- and (Z)-propenoic acids and amides

“…Treatment of resin 10 (176 mg, 0.43 Meq g Ϫ1 ) with zinc reagent 1, according to the general procedure, followed by recrystallisation from petrol-ether, gave 16 (8 mg, 55%). Mp 149-150 ЊC (lit., 17…”