Isopropyl- and tert-butylchloroacetate react with carbonyl compounds in the presence of powdered sodium hydroxide in THF, with out a catalyst, giving substituted glycidates. The process is applied for preparation of glycidates from ketones, hitherto unavailable by phase-transfer catalyzed Darzens condensation.
Chloroacetonitrile (1), a-halogenopropionitriles 4, and a-chlorophenylacetonitrile (6) react with aldehydes 2a,b,h-o and ketones 2c-g,p-t in the presence of solid NaOH in THF or DME, with out any added catalyst, affording substituted glycidonitriles 3a-t, 5a, c-g,r,s and 7a,b,i,j,u,v, respectively (Darzens condensation). The glycidonitriles 3a-h, prepared from 1 and carbonyl compounds 2a-h, are obtained in high yields, exceeding thoe reported in the literature (Table 5). Expedient results of the reactions studied are due to increased reactivity of an ions with Na+ as counterion in ethereal solvents. Investiga tion of the concentration of NaOH and the carbanion of diphenylacetonitrile in selected solvents reveals that ethereal solvents may in crease the solubility of the anions participating in Darzens condensation.
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