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K10 clay

It has been shown by Varma et al. [61] that reaction of primary and secondary amines with aldehydes and ketones is substantially accelerated by microwaves under solvent-free conditions in the presence of montmorillonite K10 clay, affording high yields of imines and enamines (Eq. 10). [Pg.76]

Rh(COD)(PPh3)2]BF4 has been shown to be a good catalyst for reductive ami-nation of acetone with 4-anilino-aniline to give the commercial product 3-IPPD. In laboratory-scale comparative experiments, this catalyst - both in homogeneous phase or immobilized on Montmorillonite K10 clay - was found to be superior to the commercially applied Pt/C catalyst (Scheme 15.11) [80]. [Pg.439]

Acidic clay catalysts can also be used in alkylation with alcohols 98 The main advantages of these catalysts are the reduced amount necessary to carry out alkylation compared with conventional Friedel-Crafts halides, possible regeneration, and good yields. Natural montmorillonite (K10 clay) doped with transition metal cations was shown to be an effective catalyst 200... [Pg.245]

A microwave-assisted Fischer indole synthesis under solvent-free conditions with Montmorillonite K10 clay modified with zinc chloride was employed in a key step of the synthesis of analogues of the cytostatic natural product, Sempervirine (Scheme 3.6)8. A dedicated laboratory microwave synthesizer was utilised. [Pg.47]

A protocol for the rapid oxidation of alcohols to carbonyl compounds has been reported with montmorillonite K10 clay-supported iron(III) nitrate (clayfen). The simple solvent-free experimental procedure involved mixing of neat substrates with clayfen, followed by microwave irradiation for 15-60 s [44]. The use of clayfen mixed with iron(III) nitrate on clay as an oxidant afforded higher yields (Scheme 4) and was more efficient, since the... [Pg.208]

A solvent-free reductive amination of carbonyl compounds using sodium borohydride supported on moist montmorillonite K10 clay also was facilitated by microwave irradiation (Scheme 8) [54]. Clay served the dual purpose of a Lewis acid and provided water from its interlayers to enhance the reducing ability of NaBH4. [Pg.211]

Heating a variety of phenols with isoprene under pressure in the presence of a zeolite catalyst affords chromans in good yield <1998S301>. Likewise, the synthesis of 2,2-dimethylchromans can be achieved via Montmorillonite K10 clay catalyzed condensation of substituted phenols with prenyl bromide <2004SL2028>. [Pg.524]

Normally, nitration of deactivated compounds (and therefore polynitration of toluene) is carried out using aggressive nitric acid - oleum mixtures. Dinitration of toluene with mixed acids produces a 4 1 ratio of 2,4- and 2,6-dinitrotoluenes, from which the former is isolated for manufacture of toluenediisocyanate (TDI) and toluenediamine, both of which are used in the manufacture of polyurethanes. Zirconium and hafnium derivatives catalyse nitration of o-nitrotoluene, but ratios of 2,4- 2,6-dinitrotoluene are modest (66 34).12 Dinitration of toluene using Claycop (copper nitrate on K10 clay), acetic anhydride and nitric acid in the presence of carbon tetrachloride produced dinitrotoluenes in a yield of 85% with a ratio of 2,4- 2,6-dinitrotoluene of 9 1.13 This method, however, requires a large excess of nitric acid, the use of an unacceptable solvent and long reaction times. The direct nitration of toluene to 2,4-dinitrotoluene using nitric acid over a zeolite P catalyst, with azeotropic removal of water, is reported to give a 2,4 2,6 ratio of 14, but full results are yet to be published.14... [Pg.234]

Rak, V. S., and Y. I. Tarasevich. 1982. Ion-exchange sorption of a-amino acids by montmorillonite with a divalent cation in the exchange complex. Teoreticheskaya i Eksperimentalnaya Khimiya 18 166-174. (in Chemical Abstracts, Vol. 96, 223829k). Ramchandani, R. K., B. S. Uphade, M. P. Vinod, R. D. Wakhankar, V. R. Choudhary, and A. Sudalai. 1997. Pd-Cu-exchanged montmorillonite K10 clay An efficient and reusable heterogeneous catalyst for vinylation of aryl halides. Chem. Commun. 2071-2072. [Pg.165]

Dhakshinamoorthy, A., Kanagaraj, K., Pitchumani, K. 2011. Ztf+-K10-clay (clayzic) as an efficient water-tolerant, solid acid catalyst for the synthesis of benzimidazoles and qui-noxalines at room temperature. Tetrahedron Letters 52 69-73. [Pg.38]

Three component condensation of N,N -dimethyl urea, paraformaldehyde and primary amines using montmorillonite K10 clay in dry media under microwave irradiation (MWI) lead to the formation of triazones whereas condensation of dimethyl urea and paraformaldehyde supported on montmorillonite KIO using MWI gave 4-oxo-oxadiazinone (Scheme 82)7 ... [Pg.225]


See other pages where K10 clay is mentioned: [Pg.123]    [Pg.124]    [Pg.86]    [Pg.224]    [Pg.102]    [Pg.60]    [Pg.87]    [Pg.87]    [Pg.112]    [Pg.112]    [Pg.212]    [Pg.364]    [Pg.58]    [Pg.234]    [Pg.561]    [Pg.664]    [Pg.444]    [Pg.192]    [Pg.41]    [Pg.62]    [Pg.76]    [Pg.375]    [Pg.380]    [Pg.393]    [Pg.395]    [Pg.308]    [Pg.381]   
See also in sourсe #XX -- [ Pg.202 ]

See also in sourсe #XX -- [ Pg.70 ]




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Montmorillonite K10 clay

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