Imidazole, 1,1 -carbonyldi

Imidazole, purification of, 48, 45 reaction with phosgene, 48, 44 Imidazole, 1,1 -carbonyldi-, 48, 44 Imidazolium chloride, 48, 46 3-Imino-l-(/)-tolylsulfonyl)pyrazolidine, from 3-amino-3-pyrazoline sulfate and />-toluenesulfonyl chloride, 48, 9... 

Condensation of the 2-quinolone 633 with ethyl 3-chloroacrylate gave the oxazole derivative 634 (79YZ813). Cyclization of 635 with l,l -carbonyldi-imidazole gave 636 (92JMC1076) (Scheme 109). 

An acid- and base-sensitive siloxycarboxylic acid was treated with AW -carbonyldi-imidazole and the resulting imidazolide (51) transformed into the desired ylide using one equivalent of salt-free methylenetriphenylphosphorane in benzene, rather than two equivalents as usually recommended. Coupling, under neutral conditions, with two equivalents of aldehyde (52) gave a mixture of diastereomeric epoxythiolates (Scheme 15).68... 

Proof of concept for this route was established by activating acid 9 with N,N -carbonyldi-imidazole (CDl) and treating it with Meldrum s acid to afford adduct 24 (Scheme 5.14). Despite its relatively high instability, adduct 24 was isolated by crystallization after aqueous work-up. Isolated 24 was easily converted to 25 in moderate yield by treatment with triazole salt 3 and Hunig s base. Because of the limited stability of intermediate 24 and in order to maximize the efficiency of the... 

The condensation of 1,4-diamines with a variety of carboxylic acid derivatives, e.g. imidate esters, orthoformic esters, /V-ethoxycarbonylthioamides (77JOC2530), nitriles and ethoxyacetylene, produces the cyclic amidine linkage —N = C(R)NH— (67AHC(8)2l, p. 40). Cyclic ureas, —NHC(0)NH—, have been similarly produced using carbonyl chloride, A, A -carbonyldi imidazole, carbon monoxide, thiocarbonyl chloride or carbon disulfide (67AHC(8)21, p. 38). 

Reaction of various aromatic or heteroaromatic diamines with iV-acyl isothiocyanates gave the corresponding benzo- or heterocycle-fused l,3,5-triazepine-2-thiones, for example, 16 (Figure 3) from 5,6-diamino-1,3-dimethyl-uracil and D-gluconyl isothiocyanate <1981CPB1832>. Cycloaddition of iVjiV -disubstituted ethylenediamines with bis(isocyanato)dimethylsilane or bis(isothiocyanato)dimethylsilane followed by treatment with 1,1 -carbonyldi-imidazole or 1,1 -thiocarbonyldiimidazole afforded a series of 1,5-disubstituted l,3,5-triazepine-2,4-diones, -2,4-dithiones, and 4-oxo-l,3,5-triazepine-2-thiones <1980AGE327>. 

Hoskins and Crout6 have carried out the selective esterification of retronecine (12) at C-9 in moderate yield with simple acids using NN -dicyclohexylcarbodi-imide. With a/3-unsaturated acids and bulky a-trisubstituted acids, the use of /VJV -carbonyldi-imidazole, with prior formation of the acyl-imidazole, gave reasonable yields of the C-9 monoesters of (12). The regiospecificity of this... 

AI-f-Butoxycarbonylalanine (10 mmol) dissolved in THF was treated with carbonyldi-imidazole (12 mmol), then the mixture stirred 50 minutes, and further treated with isobutylamine (20 mmol). After stirring 1 week, the mixture was concentrated and the residue dissolved in EtOAc. It was then washed with aqueous KHS04, water, and brine, dried using Na2S04, and the product isolated as a white solid in 83% yield. 

Techniques for the coupling of antibodies to cellulose particles or tubes were initially unreliable, time-consuming, and hazardous as they involved toxic reagents such as cyanogen bromide. A simple and convenient method is now available which employs I,I-carbonyldi-imidazole to couple antibody to microcrystalline cellulose. 

Imidazolides are powerful acylating agents. Therefore moisture has to be excluded and the acids have to be preactivated before addition of the amine. The tendency toward racemization is low, especially in DMF. The by-products of the reaction, imidazole and carbon dioxide, are easily removable. Other activating reagents (Table 6) can be applied. The advantage of COMODD and A, /V -carbonyldi-2-thione-1,3-thiazolidine is that the actival carboxylic acids are stable and isolable. 

Transformation of 1-carbamyltriazolines 49a to fused-ring systems (51) has been achieved through cyclization reaction with 1,l -carbonyldi-imidazole at 120°C for 1 hr (Scheme 22) (84ABC2913, 84JOC1073). 

Li et al. (917, 918) synthesized ioxilan carbonate by reaction of ioxilan with carbonyldi-imidazole in dimethyl sulfoxide. The reaction is specific for nonionic contrast media, protect-ingall the hydroxyl groups in the molecule and rendering it water insoluble. The reaction is given on the following page. 

Fig. 7.12. Coupling mechanisms of haptens to probes (I-V). As an example (VI), the preparation of BIO-7-NHS is shown. First NHS is coupled to biotin (a) by carbonyldi-imidazole (CDI). B-NHS then becomes reactive towards a linker. After the linker has been attached (b), an NHS is again introduced to obtain a reactive BIO-7-NHS (Costello et al., 1979). These intermediates are commercially available.

This ring is formed by reaction of neighbouring hydroxy and lactam thiocar-bonyl groups with carbonyldi-imidazole and sodium imidazolide (Naim) at or below room temperature. The product is a cyclic thiocarbonate which acylates amines under mild conditions. 

Disuccinimido carbonate (DSC) is a useful reagent for the insertion under mild conditions of a carbonyl group in diamines [3019]. A cyclization which leads to imidazo[4,5-c]pyridin-2-one is described in Section III. Carbonyldi imidazole-TEA is another reagent for this type of cyclization [3925]. Potassium ethylxan-thate (potassium ethyidithiocarbonate) is an alternative to carbon disulphide in the synthesis of the tautomeric 2-benzimidazolethiones it was first used many decades ago and usually gives good yields [3259]. The synthesis of an imidazo[4,5 c]pyridin-2-one is described in Section 111.2 [2327]. 

Cyclocarbonylation of an a-triazeno-azole in which the terminal nitrogen becomes attached to the carbonyl group is brought about by phosgene, carbonyldi-imidazole or trichloroethyl chloroformate at ambient or lower temperature. Treatment of 2-diazoimidazole (79.9) with isocyanates at — 70°C gives a high yield of the 1,4-cycloaddition product. 

Successive treatment of the selenide (322) with l,l -carbonyldi-imidazole and t-butyl hydroperoxide affords the benzoxaselenolone (323). ... 

Miscellaneous other Systems containing Three Heteroatoms. - Catechol is converted into the 1,3,2-benzodioxathiolan (503) by the action of EtNSFj. The cyclic iminodiacyl peroxide (504) is obtained from the imino-compound MeN(COCl)2 and hydrogen peroxide. The hydroxamic acid HOCPh2-CONHOH reacts with carbonyldi-imidazole to yield the dioxazolone (505). The i.r. and Raman spectra of l,3-dimethyl-l,3-diaza-2-boracyclopentanes (506 R = Cl, Br, or NMc2) have been reported. The zwitterionic salt... 

Fused Systems containing Two Six-Membered Rings (6,6) Treatment of 6-amino-5-arylazo-uracils (187) with either urea or NN -carbonyldi-imidazole gave pyrimidotriazines (188). The latter compounds were hydrolysed with alkali to triazinecarboxylic acids (189) (6-azauracil-5-carboxylic acids) (Scheme 1) ... 

M.A. Hussain, T.F. Liebert, and T. Heinze, "Acylation of cellulose with N,N0- carbonyldi-imidazole-activated acids in the novel solvent dimethyl sulfoxide/ tetrabutylammonium fluoride", Macromolecular Rapid Communications, Vol. 25, pp. 916-920,2004. 

Benzodioxins.—A synthesis of 5- and 8-hydroxy-l,3-benzodioxin-4-ones from 2,6- and 2,3-dihydroxybenzoic acid, dibromomethane, and benzaldehyde diacetate has been described. AA -Carbonyldi-imidazole reacts with 2-hydroxybenzamide to give the 1,3-benzodioxin in 72% yield (Scheme 9). Amides which lack intramolecular hydrogen-bonding react differently. ... 

L-N-Methylhistidine (20 R = Me) or its ethyl counterpart (20 R = Et) can be prepared by treating carhoxy-methylhistidine (18) with NN -carbonyldi-imidazole to give the imidazo[l,5-c]pyrimidine (19) this, upon alkylation (with RI) followed by hydrolysis (with 6M-HC1) gives the N-alkyl-histidine (20 R = Me or Et). 

Related lactams such as (101), obtained by oxidation of substituted analogues of (99), undergo base-induced ring contraction (Scheme 22). Alternatively, conversion of the sulfones to the corresponding thioamides, followed by hydrazinolysis and cyclocondensation with carbonyldi-(imidazole), affords fused-ring triazolo derivatives <83EUP72029>. 

The most prominent cellulose ester produced on the industrial scale is cellulose acetate. The reaction is usually performed with acetic anhydride and with sulfuric acid as a catalyst. To minimize heterogeneities, acetylation is allowed to run nearly to completion, and subsequently partial ester hydrolysis is initiated by the addition of water until a desirable solubility is achieved that corresponds to a DS of about 2.5. Such higher acyl homologues as propanoyl or butanoyl exhibit more thermoplastic properties. Many specialized esters such as chiral (-)-menthyloxyacetates, furan-2-carboxylates, or crown-ether-containing acylates have been prepared on the laboratory scale and characterized by NMR spectroscopy. Various procedures have been applied, using anhydrides and acyl chlorides as acylating agents in combination with such bases as pyridine, 4-dimethylaminopyridine (DMAP), or iV,iV -carbonyldi-imidazole. The substitution pattern of cellulose acetates has also been modified by postchemical enzymatic deacetylation. Cellulose 6-tosylates have been used as activated intermediates for nucleophihc substitution to afford 6-amino-6-deoxy, 6-deoxy, or 6-deoxy-6-halo-celluloses. ... 

Related Reagents. Benzotriazol-l-yloxytris(dimethyl-amino)phosphonium Hexafluorophosphate iV.iV -Carbonyldi-imidazole l-Cyclohexyl-3-(2-morpholinoethyl)carbodiimide 1,3-Dicyclohexylcarbodiimide Diphenyl Phosphorazidate Di-p-tolylcarbodiimide iV-Ethyl-5-phenylisoxazolium-3Lsul-fonate 1-Hydroxybenzotriazole Isobutene Isobutyl Chlorofor-mate l,P-Thionylimidazole. 

Carbodi-imide-mediated reaction with an alkyl spacer arm previously treated with l,r carbonyldi-imidazole-activated agarose Glutaraldehyde-mediated reaction with sub-micron ferrite particles... 

Thiobenzamide and 3 eqs. NEt3 added to anhydrous acetonitrile, cooled to —20°, a pre-formed soln. of 2-bromobutyrylimidazole (prepared by adding N,N -carbonyldi-imidazole to 2-bromobutyric acid in acetonitrile and stirring for 10 min at 0°) added dropwise over several min, stirred at —20° for 30 min, rcrr-butyldimethylsilyl chloride in acetonitrile added in one portion, stirred for 3 h at 0°, and poured into cold water... 

---