9-carboranyl methyl

BORONCOMPOUNDS - COMMERCIAL ASPECTS] (Vol 4) Carboranyl methyl propionate [62906-37-0]... 

Reduction of the ditellurium derivatives with sodium borohydride in ethanol and reaction of the resulting sodium 9-carboranetellurolate with methyl iodide yielded 9-carboranyl methyl telluriums3,4 (s.p. 185). 

The ditellurium compounds were treated with sodium borohydride and the tellurols reacted with methyl iodide to produce 9-carboranyl methyl tellurium derivatives1 (see p. 5). 

The methylation of sodium 9-or//tocarboranetellurolate2,3 and 9-wietucarboranetelluro-late2 with methyl iodide yielded 9-carboranyl methyl tellurium compounds. 

Infrared spectroscopy is widely used for the structural determination of tautomers, isomers conformers of various nitroimidazoles [42, 1043], Vibration spectra of different 1-alkyl [362]-, l-(trialkylsilylalkyl)-2-methyl-4-nitroimidazoles [363], allylated 4-nitroimidazoles [364], dinitroimidazoles [428] have been studied. The vibration frequencies of some medicinal compounds on the base nitroimidazoles, for example, diasteriomeric nido-carboranyl misonidazole congeners [389], antiviral agents [452], and adrenergic-receptor agonists [454] are analyzed. In the literature the number of publications devoted to vibration spectra is rather limited and, as a rule, the absorption band frequencies of nitroimidazoles are considered in synthetic works concerned with structure identification such as, for example, [354, 429, 461-464,468-471, 1044-1047],... 

The pKa of the methylene protons of 7 is close to that of cyanacetic ester. Thus, it was interesting to compare the reactions of these two species. We found that 7 can be acylated by various carboxylic acid halides, leading to compound 11. According to IR and NMR data 11 exists mostly as the enol-form, due to the influence of the carboranyl substituent, which strongly stabilizes conjugated double bonds.13 Compound 11 is a useful synthon for the preparation of heterocyclic compounds. It can be methylated, chlorinated and acylated twice ( compound 13). Compound 13 gives an adduct with phenylhydrazine (scheme 6). 

Carboranyl acid halides can be very easy prepared. We have studied the acylation of malononitrile and acetoacetic ester by methylcarboranyl carboxylic acid chloride (15). The reaction with malononitrile leads to the compound 17a, which exists also as a enol form, similar to compound 13. Compound 17a can be methylated to give compound 17b, a novel synthon for the preparation of wide range of heterocyclic compounds (Scheme 7). 

Poly(w-carboranyl-siloxane) elastomers containing a mixture of di-methyl-and methyl(phenyl)-silyl units were synthesised using the Ferric Chloride catalyzed condensation reaction between di-chloro-di-organosilane and 1,7-bis(di-methyl(methoxy)silyl)-/w-carborane. Silica Nano tubes synthesised using i 7situ growth of DL Tartaric acid nanocrystals and concurrent sol-gel hydrolysis and condensation of silane. 

Carboranyl derivatives of lanthanum, thulium and ytterbium are formed when the C-mercuro derivatives of methyl- and phenylcarboranes react with the rare earth metals in tetrahydrofuran at 20°C (Suleimanov et al., 1982a), or from the lithium derivatives of methyl- and phenylcarboranes with the rare earth trichlorides in benzene-ether at 20°C (Bregadze et al., 1983) as complexes with THF. A carboranyl derivative with a thulium-boron bond is also described. The reaction (eq. 62) may proceed via the formation of B-Tm-C derivatives, followed by disproportionation. 

Carboranes. A soln. of butylsulfenyl chloride in CCI4 added dropwise at -10 to 0 under argon to a stirred soln. of diethyl (methyl-o-carboranyl)phosphonite in abs. CCI4, and distilled O-ethyl S-butyl (methyl-o-carboranyl)monothiolphos-phonate. Y 90%. A. N. Degtyarev et al., Izvest. 7975, 2369 C. A. 80, 37208. 

A synthesis of 2 -0-methyluridine has been carried out by a procedure in which the 3, 5 -0-TIPDS derivative of uridine was protected at N-3 by the p-methoxybenzyl group,208 and the "wobble position" nucleoside 2 -0-methyl-5-(methoxycarboxylmethyl)uridine has also been prepared by similar means.209 The 2 -0-allyl derivative (141) of uridine is accessible by a palladium-catalysed decarboxylation of (142), and a similar reaction is possible on an adenosine derivative.210 2 -0-Propargyl uridine can be prepared via the 2, 3 -0-dibutylstannylene derivative the triple bond of this derivative could then be converted into an unusual carboranyl group, the resultant structure being of potential use in the neutron capture therapy of cancer.211 A conference report has discussed the use of 2-(methylthio)-phenylthiomethyl (MPTM) ethers for protection of the 2 -hydroxyl group in oligoribonucleotide synthesis.212... 

Ci6H6i,B5oP2 CgHs, Penta(methyl-o-carboranyl)diphosphine benzene solvate, 45B, 737... 

A -methylated derivatives 176 and 177, the alteration led to a decreased binding between avidin and streptavidin. The carboranyl compounds 183 and 186 showed somewhat better in vivo stability than 176, as was evident by a higher level of radioactivity in the neck region (thyroid) caused by the latter. The radioactivity in the neck region (thyroid) as a result of deastatination of 179 was significantly higher than the radioactivity from deiodination of 178 indicating a week C- "At bond in the former. Similarly, the B- "At bonds in 184 and 187 appeared to be less stable than the bonds in 183 and 186 but differences were not nearly as pronounced as between the C- " At and the C- l bonds in 178 and 179, respectively. 

The use of liposomes as boron delivery vehicles for BNCT has been extensively studied, since liposomes can transport large amounts of boronated molecules, both hydrophobic and hydrophilic in nature, selectively into tumor cells. Three methods for incorporation of boron into liposomes have been reported incorporation of hydrophobic molecules into lipid bilayers, entrapment of hydrophilic molecules into the liposomes aqueous core, and the use of boronated lipids. Recently, PEG-based liposomes (DPPC/cholesterol/DSPC-PEG2000) have been used as effective carriers of boronated compounds within tumor tissues. Intraveuously injected B-PEG-liposomes on human pancreatic carcinoma xenografts in nude mice inhibited tumor growth after thermal neutron irradiation. The cationic liposome formulation (DOTAP/DOPC/DOPE) was used to deliver ortho-carboranyl P-lactoside (LCOB) aud l-methyl-ort/j< -carboranyl-2-hexylthioporphyrazine (H2PZ-COB) within DHD/K12/TRb (DHD) rat colon carcinoma and B16-F10 murine melanoma cell lines. Results from these studies show that a thirty-fold increase on the cellular uptake of B was obtained for the boronated compounds in the liposome formulation as compared with that of the BPA-fructose complex. 

Spielvogel, B. R Rana, G. Vyakaranam, K. Grelek, K. Dicke, K. E. Dolash, B. D. Li, S.-J. et al., A novel approach to the syntheses of functionalized, water-soluble icosahedral carboranyl anions. Crystal structure of methyl N-[(trimethylamineboiyl)carbonyl]-L- tyrosinate A synthon for novel carboranyl-peptides. Collect Czech Chem. Commun. 2002, 67, 1095—1108. 

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