ChemInform Abstract: A Novel Route to m‐Aminobenzotrifluoride.

Abstract

m‐Nitrobenzotrichloride (I) is fluorinated and reduced simultaneously by treatment with an anhydrous hydrogen fluoride/ammonium tetrafluoride complex to give m‐aminobenzotrifluoride (II).

Room‐Temperature Nucleophilic Aromatic Fluorination: Experimental and Theoretical Studies

“…A comparison of the mono‐ and dichloropyridine examples shows that a second electronegative substituent accelerates substitution: fluorination of 2‐chloropyridine requires 14 days, whereas 2,6‐dichloropyridine is exhaustively fluorinated in 90 minutes under identical conditions. In comparison, typical Halex fluorinations of 2,6‐dichloropyridine require heating at 150 °C for ten hours 20–23. Chloropyridine substrates bearing more strongly electron‐withdrawing (trifluoromethyl or carbonyl) substituents are also fluorinated rapidly, as are several other heterocyclic derivatives.…”

Synthesis and Low Temperature Spectroscopic Observation of 1,3,5-Trioxane-2,4,6-Trione: The Cyclic Trimer of Carbon Dioxide

“…The third step of dehydrohalogenating 3a to the hexamethyl triolefin-trioxane 2a was problematic. In our hands a patented procedure for preparation of compound 2a (Route A, reaction of 3a with sodium hydroxide dispersed in dimethylheptanol at 185 °C) produced no yield of product. An alternate approach of using potassium tert -butoxide in THF (Route B) afforded 2a in good yield.…”

“…An alternate approach of using potassium tert -butoxide in THF (Route B) afforded 2a in good yield. Compound 2a prepared via Route B is a liquid while that reported from Route A was a solid with a very broad melting point (54–62 °C) . A thorough analysis of this product was conducted ( 1 H NMR, 13 C NMR, IR, UV–vis, HR-MS, elemental analysis and differential scanning calorimetry; see Experimental Section and Supporting Information for data and discussion), and these results are in good agreement with the structure assigned to compound 2a .…”

“…Trimerization of the commercially available aqueous solution of 5 with concentrated H 2 SO 4 produced low yields (26%) of 3b and often inconsistent results. Multiple attempts to dehydrohalogenate trioxane 3b , using either the previously reported conditions (Route A) or our modified procedure (Route B) failed to yield the desired unsubstituted triolefin-trioxane 2b . Confident in the structure of the methyl substituted triolefin-trioxane and the reproducibility of our procedure; our focus was placed on the oxidation chemistry of 2a .…”

“…Found: C, 68.48; H; 8.76. Note: in an earlier published procedure for compounds 2a and 2b difficulties were encountered in both obtaining the products and reproducing characterization data (see Supporting Information for detailed discussion and data).…”