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Usage

InChI:InChI=1S/C14H26B2N4/c1-5-15(6-2)17-11-9-13-19(17)16(7-3,8-4)20-14-10-12-18(15)20/h9-14H,5-8H2,1-4H3

Upstream product

• 288-13-1 NH-pyrazole 
• 7318-84-5 Tetraethyldiboroxan 
• 77172-65-7 B(N(CH₃)CH₂CH₂N(CH₃))(N₂C₃H₃) 
• 7397-47-9 (dimethylamino)diethylborane 
• 97-94-9 triethyl borane 
• 75-22-9 trimethylamine-borane 
• 99604-53-2 C2H5B(μ-C3H3N2)2(μ-OBC2H5O)BC2H5 
• 116928-37-1 2,2,4,4-tetraethyl-3-oxonia-1-azonia-5-aza-2,4-diboratabicyclo{3.3.0}octa-6,8-diene 
• 76356-55-3 1,3-dimethyl-2-(pyrazol-1'-yl)-1,3,2-diazaboracyclohexane 
• 264884-12-0 (1-pyrazolyl)diethylborane pyrazole adduct 
• 217324-49-7 2,2-dimethylpropanoyloxydiethylborane pyrazole complex 
• 217324-51-1 C₃H₃N₂(B(C₂H₅)2)2O₂CC(CH₃)3 
• 129391-20-4 triethylborane pyrazole complex 

Relevant academic research and scientific papers

Catalyzed reaction of triethylborane with pyrazole

The reaction of triethylborane with pyrazole leading to 4,4,8,8-tetraethylpyrazabole was found to be catalyzed by carboxylic acids. 2,2′-Dimethylpropanoic (pivalic) or benzoic acids act as catalysts in this reaction. Intermediates occurring in the catalyt

Pyrazole complexes of three-coordinated boranes

Both BF3 and B(C2H5)3 form 1:1 molar complexes with pyrazole (=Hpz) and C-substituted derivatives thereof (=Hpz*). Provided the pyrazole is a relatively strong base, the BF3 complexes slowly decompose on prolonged standing at room temperature with the elimination of HF to form the corresponding dimeric 1-pyrazolylboranes = pyrazaboles, e.g., F2B(μ-pz)2BF2. Deprotonation of Hpz·B(C2H5)3 with NaH yields the ion [(C2H5)3B(pz)]-, and the salt K[(C2H5)2B(pz)2] is obtained on heating of an equimolar mixture of Hpz·B(C2H5)3 and Kpz in Hpz. Species of the type K[R2B(pz)2] are also obtained by the reaction of (dimethylamino)diorganylboranes, (CH3)2NBR2, with Kpz and Hpz; they were converted to the representative Pd complexes Pd[(μ-pz)2B(C2H5)2]2 and R2B(μ-pz)2Pd(π-CH2CHCH2) (R = C2H5, n-C3H7, C6H5), respectively. Interaction of (CH3)2NBR2 with 1 molar equiv of Hpz gives 1:1 complexes of the type (CH3)2HN·BR2(pz), which can react with an additional molar equivalent of Hpz at elevated temperatures to form Hpz·BR2(pz) = R2B(pz)2H, or form mixtures of the desired compound with the pyrazabole relative R2B(μ-pz)[μ-N(CH3)2]BR2. Steric factors may prevent the intermediate formation of the 1:1 complexes to lead directly to Hpz·BR2(pz). The complexes Hpz·BR2(pz) can be thermolyzed to yield the pyrazaboles R2B(μ-pz)2BR2. However, whereas the reaction of [(CH3)2NBF2]2 with Hpz ultimately yields the pyrazabole F2B(μ-pz)2BF2, the reaction of the cited aminoborane with Hpz and Kpz causes redistribution of fluorine and K[F3B(pz)] is obtained as the only product containing B-F bonds. The complex (pz)2B(C2H5)(H2NCH3) is formed on reaction of the borazine (C2H5BNCH3)3 with a large excess of Hpz, and H-(pz)3B(NHCH3) is obtained in analogous fashion originating from the borazine [(CH3)2NBNCH3]3. The reaction of [(C-H3)2NNH]3B with excess of Hpz yields the complex (CH3)2NNH2·B(pz)3.

Novel Substituted B2ElVIN2 Heterocycles

The bis(diorganoboryl) chalcogenides (R2B)2O , (R2B)2S , and (R2B)2Se react with pyrazole (Pz) and its derivatives 3-methylpyrazole (3-MePz) and indazole (benzo-Pz) to form in high yields (65 - 92 percent) stable 1 : 1 adducts . 1H-, 13C-, 11B-NMR spectra and X-ray analyses (of 2 and 6) show a basic structure with a central B2ElN2 (El = O, S, Se) heterocycle.The reaction of 2 with R2BH and the thermolysis of 4 give the dimeric 1-pyrazolylboranes 9a and 9b, respectively. -Keywords: Bis(diorganoboryl)chalcogenides / Pyrazaboles / Pyrazoles

Chemical behavior and structure of triply bridged pyrazaboles of the type RB(μ-pz)2(μ-OBRO)BR

Triply bridged pyrazaboles of the type RB(μ-pz)2(μ-OBRO)BR (1, R = C2H5, C6H5; Hpz = pyrazole) are thermally quite stable and can be sublimed without decomposition even under atmospheric pressure. At room temperature they are resistant to water but are not soluble. Dissolution of 1 in protonic solvents occurs with complete breakdown of the molecule. Halogenation of 1 (R = C2H5) with SOCl2 yields the pyrazabole RClB(μ-pz)2BRCl. The latter compound is a valuable material for the preparation of various other pyrazaboles. Thus, reaction with alkali-metal alkoxide or with alcohol in the presence of triethylamine gives access to R(R′O)B(μ-pz)2BR(OR′) (R′ = CH3, C2H5), the first examples of B-alkoxypyrazaboles; with (CX3CO)2O (X = H, F), the species with R′ = CX3CO are obtained. The crystal and molecular structures of 1 with R = C2H5 were determined. The molecule crystallizes in the monoclinic system in space group P21/c with a = 7.587 (2) A?, b = 12.415 (2) A?, c = 16.387 (3) A?, β = 90.50 (2)°, and Z = 4.

Boron-nitrogen compounds. 110. Reactions of boroxins and diboroxanes with pyrazole

Tetraorganyldiboryl oxides (1,3-diboroxanes) (R2B)2O (R = C2H5, C6H5), react at elevated temperatures with excess pyrazole, Hpz, to give an essentially quantitative yield of the corresponding pyrazabole, R2B(μ-pz)2BR2. The 1,3-diboroxane [(CH3)2NBR]2O (R = C6H5) reacts with Hpz in refluxing toluene to form the triply bridged pyrazabole RBB(μ-pz)2(μ-OBRO)BR as the major product besides substantial quantities of the diboroxane derivative [(pz)RB(μ-pz)2BR]2O. In the latter, two pyrazabole moieties are linked by an oxygen bridge between boron atoms. The boroxin adduct (-BRO-)3·Hpz (R = C6H5) is obtained on direct interaction of triphenylboroxin with pyrazole at room temperature. As based on NMR data, two boron atoms of the boroxin ring are coordinated to pyrazole nitrogen atoms and the N-bonded proton is delocalized. In contrast, all three boron atoms are coordinated in 1:1 molar mixtures of the boroxin with either 3,5-dimethylpyrazole or imidazole. The adduct (-BRO-)3·3Hpz was identified as a transient species. It undergoes a slow condensation on standing in solution at room temperature. At elevated temperatures the reaction progresses readily to yield the triply bridged pyrazabole RB(μ-pz)2(μ-OBRO)BR. When a neat mixture of the two reagents is refluxed, the pyrazabole R2B(μ-pz)2BR2 is obtained. Triethylboroxin and pyrazole interact readily even at room temperature beyond mere complexation to form RB(μ-pz)2(μ-OBRO)BR with R = C2H5. Additional pyrazole and even minor increases in temperature promote the condensation process.

BORON-NITROGEN COMPOUNDS. XCVIII. PREPARATION AND REACTIONS OF 2-(AZOL-1'-YL)-1,3,2-DIAZABORACYCLOALKANES

The preparation of several 1,3-dimethyl-2-(azol-1'-yl)-1,3,2-diazaboracyclohexanes is described and their NMR spectra are interpreted.The reaction of 2-(pyrazol-1'-yl)-1,3,2-diazaboracyclohexanes with pyrazoles was found to lead to 1/1 molar adducts which

BORON-NITROGEN COMPOUNDS. XCVI. STUDIES OF THE CHEMICAL BEHAVIOR OF MONOMERIC PYRAZOL-1-YLBORANES

Two 1,3-dimethyl-2-(methylpyrazol-1'-yl)-1,3,2-diazaboracyclopentanes have been prepared.The interaction of such monomeric pyrazol-1-ylboranes containing trigonal boron with pyrazoles has been examined and 1/1 molar addition compounds have been identified and isolated.Labelling experiments support spectroscopic evidence to suggest a mobile bridging hydrogen in the cited adducts at ambient temperature and above.Monomeric 1,3-dimethyl-2-(pyrazol-1'-yl)-1,3,2-diazaboracyclopentane reacts with (dimethylamino)dialkylboranes by an exchange of the pyrazolyl with the dimethylamino group.A cyclic transition state involving a B2N3 ring system is suggested for this process in which the corresponding 2-dimethylamino-1,3,2-diazaboracyclopentane and B-tetraalkylpyrazaboles are the final products.The latter are also found among the reaction products of pyrazole adducts of monomeric pyrazol-1-ylboranes with (dimethylamino)dialkylboranes.The interaction of (dimethylamino)dialkylboranes with pyrazole gives B-tetraalkylpyrazaboles in essentially quantitative yield.