Chloroformate adamantan

Magnesium powder. Ferric oxide. Aluminum powder Potassium permanganate, Adamantane, Bromine, Sodium sulfite. Hydrochloric acid. Glacial acetic acid. Aluminum foU, Toluene, Methylene iodide. Acetonitrile, Tetrahydrofuran, Sodium hydroxide. Acetone, Magnesium sulfate. Aluminum chloride. Chloroform... 

Gas-chromatographic and infrared analysis indicate no detectable amount of starting alcohol. Proton magnetic resonance of adamantane 2 (chloroform-d) yields a series of multiplets centered at 8 1.62, 1.86, 2.18. 

A solution of betamethasone (1.0 g) in dry tetrahydrofuran (40 ml) was treated with adamantane carbonyl chloride (about 2.2 equivalents) in dry tetrahydrofuran (5 ml) and then pyridine (0.8 ml) was added. The mixture was refluxed for 6 h and then most of the solvent was boiled off and the residue extracted with chloroform to afford a froth. The ether soluble portion of this froth was dissolved in chloroform and extracted repeatedly with dilute sodium bicarbonate solution. Evaporation of the chloroform layer gave a froth which was further purified by chromatography and crystallisation from chloroform-petroleum ether to yield betamethasone 21-adamantane-l -carboxylate melting point 256°-259°C (dec.). 

The reagents for the synthesis of Al -l-adamantyloxycarbonyl amino acid derivatives are similar to those used for other urethane-type protecting groups (Scheme 36). Although the related 1-adamantyl chloroformate (Adoc-Cl, 68) is obtained as crystalline solid, the acylation of amino acids under Schotten-Baumann conditions leads to significant decomposition of the reagent and thus its use does not result in satisfactory yields in all cases. Better results are obtained with 1-adamantyl fluoroformate (Adoc-F, 69) (yields of A -Adoc amino acids 85-95%)P I which is conunerciaUy available or readily prepared from adamantan-l-ol and... 

Nucleoside synthesis Adamantane-1-carboxylic acid chloride. Bis-(p-nitrophenyl)hydrogen phosphate. /3,)3, 8-Tribromoethyl chloroformate. 

Hydroxyl group Adamantane-l-carboxylic acid chloride. 0-Benzoylpropionic acid. Ethyl vinyl ether. 4-Methoxy-5,6-dihydro-2H-pyrane. p-Nitrophenyl chloroformate. 

By pathway B, N(2),N(6)-ditolylsulfonyl-4 8 -dibromo-2,6-diaza-adamantane 107) was synthesized (22%) by treatment of the bicyclic sulfonamide-diene 62 with N,N-dibromo-p-tolylsulfonamide in chloroform at low temperature. Hydrogenolysis... 

Even electrophilic fluorination of alkanes has been reported. F2 and fluoroxytrifluoro-methane have been used to fluorinate tertiary centers in steroids and adamantanes by Barton and coworkers ". The electrophilic nature of a reaction involving polarized but not cationic fluorine species has been invoked. Gal and Rozen have carried out direct electrophilic fluorination of hydrocarbons in the presence of chloroform. F2 appears to be strongly polarized in chloroform (hydrogen bonding with the acidic proton of CHCI3). However, so far no positively charged fluorine species (fluoronium ion) is known in solution chemistry. 

A mixture of 8.0 g (4.2 mmol) methoxynoria, 8.2 g (60 mmol) K2CO3, and 0.064 g (0.2 mmol) tetrabutylammonium bromide in 95 ml NMP (1-methyl-2-pyrrolidone) is stirred at 60°C for 3 h. After that, a solution of 4.3 g (1.5 mmol) BMA (2-bromoacetyloxy-2-methyladamantane) in 5 ml NMP is added slowly to the resultant mixture, poured into chloroform, and washed with 0.1 M oxalic acid aqueous solution and water. The organic layer is dried over MgS04, and the solution is concentrated by rotary evaporator. The concentrated solution is added to methanol to obtain the white solid. The resulting precipitate is collected by vacuum filtration and dried at 60°C in vacuo for 12 hr. Thus, adamantylester of noria is finally obtained. The chemical structure of noria profecfed by adamantane is shown in Figure 3.18. 

Chloroform added dropwise during 6 hrs. to a vigorously stirred emulsion of adamantane, aq. 50%-NaOH, triethylbenzylammonium chloride, and benzene. 

By ( clization of N-(l-adamantoyl)-N -methyl-o-phenylenediamine in absolute chloroform and alcohol environment, in the presence of polyphosphoric aeid ester (ppe), l-methyl-2-(adamantyl)benzimidazole (79) is obtained with 35% yield. 6-nitrobenzimidazole-2-earboxylic acid-(l-adamantylamide)-l-oxyde (80) was obtained with 3% yield by treatment of l-(N-2,4-dinitro-phenylgli( lamino)adamantane in pH 8.5 phosphate buffer, at 90 C during 136 hours. 

Pyridine 1-oxide reacts with adamantane-1-thiol in acetic anhydride to give 2- and 3-(l-adamantanethio)pyridines and their tetrahydropyridine analogues. Corresponding butylthio-substituted pyridines are obtained using Bu SH or Bu SH in this reaction in the presence of a chloroformic acid derivative. No complications arise in the use of 3-bromopyridine 1-oxide and KSH for the synthesis of 3,3 -dipyridyl sulphide. 2-Methyl- or 2-phenyl-pyridine is converted into its 5-alkylthio-homologue by reaction of the pyridine-MeLi adduct with a dialkyl disulphide. ... 

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