Formation of N-substituted trichloroacetamides from amines and hexachloroacetone

Abstract

Procedures are described for converting primary amines into their well-crystalline trichloroacetyl-derivatives by treatment with hexachloroacetone under mild conditions. Although secondary aromatic N-methylamines are unaffected by hexachloroacetone, saturated heterocyclic amines react vigorously.A mechanistic study using 2-amino-4-t-butylthiazole showed that the reaction is first order in hexachloroacetone, second order in amine, and base-catalysed; there is no appreciable kinetic isotope (H/D) effect nor accumulation of intermediates during the reaction. A sequence which accommodates these results is suggested.N-SUBSTITUTED trichloroacetamides can be prepared by treating primary and secondary amines with trichloroacetyl chloride and primary amines with ethyl trichloroacetate,2 and, in low yield, by rearrangement of alkyl acet imidates .3 Some Nt richloroacet ylphen ylamines have also been obtained from the amines using aqueous hexachloroacetone; this ketone (in dimethyl sulphoxide) has been used for the trichloroacetylation of dipep tide^.^ The present work stemmed from the observation that 4-methyl-and 5-ethyl-2-trichloroacetamidothiazole, originally prepared using trichloroacetyl chloride,6 are formed readily from the 2-aminothiazoles and hexachloroacetone. A mechanistic investigation

Photo-on-Demand In Situ Synthesis of N-Substituted Trichloroacetamides with Tetrachloroethylene and Their Conversions to Ureas, Carbamates, and Polyurethanes

“…1 H and 13 C NMR spectra are in agreement with those reported in the literature. 29 White solid, mp 41.0−44.5 °C. NO,229.9901;found,229.9894.…”

“…1 H and 13 C NMR spectra are in agreement with those reported in the literature. 29 White solid, mp 41.0–44.5 °C. 1 H NMR (400 MHz, CDCl 3 , 293 K): δ/ppm 3.75 (br, 4H), 1.69 (br s, 6H); 13 C NMR (100 MHz, CDCl 3 , 293 K): δ/ppm 159.0, 93.4, 49.4, 47.9, 47.0, 25.6, 24.1.…”

“…1 H and 13 C NMR spectra are in agreement with those reported in the literature. 29 1 H NMR (400 MHz, CDCl 3 , 293 K): δ/ppm 6.45 (br s, 1H, NH), 4.11–4.03 (m, 1H), 1.27 (d, J = 6.8 Hz, 6H, methyl); 13 C NMR (100 MHz, CDCl 3 , 293 K): δ/ppm 160.9, 92.8, 44.0, 22.1; IR (ATR) ν: 3309, 2979, 1683, 1525, 1252, 1148, 868, 819, 637 cm –1 ; HRMS (ESI orbitrap) m / z : [M + Na] + calcd for C 5 H 8 Cl 3 NONa, 225.9564; found, 225.9563.…”

Trichloroacetylation of Some Cyclic Enamines.

“…Compound 3 has been directly synthesized by the reaction of morpholine in chloroform with hexachloroacetone, in the literature. 9) In case of cyclopentanone enamines under the same reaction conditions, both the 1-(4-morpholino)cyclopentene (1b) and 1-(1-pyrrolidinyl)cyclopentene (1d) were converted directly to the corresponding triketone, 2,6-di(trichloroacetyl)cyclopentanone (7), in 45 and 55% yields, respectively. The reaction of compound 1b also gave N-acetylated product, compound 3, in 35% yield.…”

N,N-disubstituted 2-aminothiazole-5-carboxylates: preparation and rotation of functional groups

“…'H n.m.r. signals(6 values at 305 K) of NCH3 groups are for solutions in CDC13. The AGS values (kJ mol-', statistical error f 4 kJ mol-I, obtained using solutions in CDzClz over the range 180-305 K, are the activation energies for rotation about the C(2)-N bond at 298 K. The 13C n.m.r.…”