Bis l-pyrazolyl propane

A 100-mL, round-bottomed flask is charged with 17.02 g (0.250 mole) of pyrazole, 10,42 g (0.100 mole) of 2,2-dimethoxypropane, (distilled from sodium hydride and stored under N2), 20-30 mg of p-toluenesulfonic acid monohydrate, and a 1-in. egg-stirring bar. The flask is fitted with a 20-cm Vigreux column topped by a short-path distillation apparatus. The mixture is heated to reflux and methanol (about 8 mL) is slowly removed by distillation. 

The reaction is cooled to room temperature and approximately 50 mL of toluene and 35 mL of 5% sodium carbonate solution are added. The organic layer is separated, extracted with 3 x 50 mL of 5% sodium carbonate solution, dried over MgSO, and filtered. The toluene is removed on a rotary evaporator and the residue dissolved in 20 mL of methylene chloride. The concentrated solution is absorbed at the top of a column of alumina (2 x 20 cm ca. 100 g of activity III) and eluted with 150 mL of CH2CI2 to remove any unreacted pyrazole. The solvent is removed on a rotary evaporator and the solid is recrystallized from 100 mL hexanes to give 10.28 g of the product as white crystals melting at 84-86°C. A second crop of product (0.60 g) can be obtained by concentration of the filtrate, giving an overall yield of 10.88 g (62%) based on 2,2-dimethoxypropane. 

---

N4C21H20, 2,2-bis(3-phenyl-l-pyrazolyl) propane, 32 53 N4C22H14, 2,3-bis(2-pyridyl)-... 

Co = Catechol oxidase He = Hemocyanin Tyr = Tyrosinase MePy2 = Al,Al-bis(2-pyridylethyl)methylamine TACN = 1,3,5-triazocyclononane TMPA = Tris[(2-pyridyl) methyl]amine XYL-0 = a, a -bis[Al,Al-bis(2-pyridylethyl) amino]-m-xylene-2-olate XYL = a, a -bis[Al,Al-bis(2-pyri-dylethyl)amino]-m-xylene XYL-R = Meta substituted a,a bis[Al,Al-bis(2-pyridylethyl)amino]-m-xylene N3 = N, N, Al, Al -Tetrakis-(2-pyridin-2-yl-ethyl)-propane-1,2-diamine N4 = Al,Al,Al, Al -Tetrakis-(2-pyridin-2-yl-ethyl)-butane-1,2-diamine N5 = Al,A,lV, Al -Tetrakis-(2-pyridin-2-yl-ethyl)-pentane-1,2-diamine HB(3,5-Pr2pz)3 = Hydrotris(3, 5-diisopropyl-l-pyrazolyl) borate XAS = X-ray absorption spectroscopy EXAFS = Extended X-ray absorption fine structure rR = resonance Raman. 

The novel tetrabasic ligand l,3-bis(5-methylpyrazole-3-carboxamido)propane forms a trinuc-lear Co111 Co11 Co111 complex (196). The tetradentate diamide-pyrazolyl chelates encircle the terminal trivalent metal ions while the central divalent Co is in a distorted tetrahedral environment provided by the four bridging pyrazolyl rings.881... 

Figure 1. XANES spectra for crystallographically characterized Mn(II), Mn(III), and Mn(IV) model compounds. Long dashed lines indicate Mn(II) compounds solid lines indicate Mn(III) compounds short dashed lines indicate Mn(IV) complexes. The models chosen to illustrate this phenomenon are[Mn(ll)HB(3,5-iPr2pz) 3]2(OH) 2and(pyrazolyl) 2Mn(OCfi3) 3Mn(ll) (HB 3,5-iPr2pz)3 [where HB(3,5-iPr2pz)3 is hydrotris(3,5-diisopropyl-1-pyrazolyl borate) Mn(II)(hexakisimidazole)Cl2 Mn(III)(acac)3 Mn(III)2, [2-OH-(5-Cl-SAL)PN]2(CH3OH), [Mn(IV) (n2-0) (SALPN)]2, and [Mn(IV)-(SALPN)]2(h2-0)(h2-OH) [where SALPN is l,3-bis(salicylideneimanato) propane] [Mn(III) (SALAHP) (AcO)]2 [where SALAHP is 3-(salicylideneim-inato)-2-methyl- 1,3-dihydroxy propane] and Mn(IV) (SALADHP) 2 [where SALADHP is the dianion of 2-methy 1-2-(salicylideneamino)-1,3-dihydroxy-propane].

---