Synthesis of 1,4-Diazabicyclo [2,2,2] Octane with Alkaline Earth Phosphate Catalysts

Abstract

Here we report on the discovery and development of a new catalyst based on strontium hydrogen phosphate for efficient production of DABCO, 1,4-diazabicyclo [2,2,2] octane. It was brought from initial lab scale discovery to commercial use in less than 1 year. It provides significant value for production of DABCO via much higher selectivity and nearly double the productivity of the silica–alumina material used as the previous commercial catalyst. The value is not only in higher observed productivity but also in large savings in feedstock costs derived from the improved reaction selectivity and also a much longer effective useful lifetime than the previous silica–alumina.

The versatility of DABCO as a reagent in organic synthesis: a review

“…Organic & Biomolecular Chemistry Houdry lab due to calcination of compounds of the type H 2 NCH 2 CH 2 X (X = OH, NH 2 , or NHR) (6) using alumina supported catalysts, as illustrated in Scheme 3. [20][21][22][23] Since 1950, after the discovery of DABCO, various researchers and research groups made attempts to synthetically prepare the skeleton anticipating its probable applications in various branches of Chemistry. [24][25][26][27][28][29][30][31][32][33][34][35][36][37] Table 1 showcases a few attempts made by the researchers to synthesize DABCO.…”

“…Despite the fact that numerous methods have been used to synthesize DABCO (1), its production has been plagued for a long time due to its low yield, space time yield catalyst (silica-alumina catalyst) and selectivity of the desired product due to the formation of a large number of side products with high molecular weights. 23 Since the above catalysts were inefficient in some way, several catalysts were evaluated based on their surface acidity distribution, surface area, porosity using BET, Hg and N 2 porosity, acidity of NH 3 desorption and calorimetry using organic amine probes such as N-butyl amine. Catalysts used included Scheme 3 Synthesis of DABCO from H 2 NCH 2 CH 2 X (X = OH, NH 2 , or NHR) (6) with alumina supported catalysts.…”

“…30% to 46% A few years later, exceptional work was done by them to prepare DABCO (1) from ethylenediamine and piperazine mixture over a TS-1 type zeolite. 23 The selectivity of the desired product was ∼95% with a conversion rate >95% 25,36 27% to 79% Scheme 4 Intramolecular pathway for the production of DABCO. 23 Organic & Biomolecular Chemistry Review gamma-alumina, AlPO 4 , boron phosphate, silica-alumina and certain solid acid catalysts such as phosphate doped oxide, apatite type materials Cr 2 O 3 /Al 2 O 3 and others.…”

“…23 The selectivity of the desired product was ∼95% with a conversion rate >95% 25,36 27% to 79% Scheme 4 Intramolecular pathway for the production of DABCO. 23 Organic & Biomolecular Chemistry Review gamma-alumina, AlPO 4 , boron phosphate, silica-alumina and certain solid acid catalysts such as phosphate doped oxide, apatite type materials Cr 2 O 3 /Al 2 O 3 and others. Two key findings were obtained from the preceding experiments.…”

“…As a result, certain catalysts were omitted from the list, primarily pyrophosphates, ortho arsenates and hydrosulphates with valencies of +1, +2 and +3. 23…”