25899-50-7Relevant articles and documents
Rational design of efficient steric catalyst for isomerization of 2-methyl-3-butenenitrile
Han, Minghan,Liu, Kaikai,Wang, Tiefeng
, (2020/10/22)
The catalytic isomerization of 2-methyl-3-butenenitrile (2M3BN), a model reaction in the DuPont process, has been performed using NiL4 (L=tri-O-p-tolyl phosphite) as a catalyst. The lowered catalytic activity in the isomerization with coexistence of 2-pentenenitrile (2PN) and 2-methyl-2-butenenitrile (2M2BN) indicates that both 2PN and 2M2BN are the catalyst inhibitors, and the quantitative relationship between the conversion of 2M3BN and the content of 2M2BN and 2PN is provided. DFT calculation results suggest that the inhibition effect is attributed to the generation of dead-end intermediates (2PN)NiL2 and (2M2BN)NiL2, both of which take nickel atom out of the catalytic cycle in the isomerization process. To suppress the inhibition effect, new catalytic intermediates are rationally designed based on their computational %Vbur. An efficient method that adding extra ligand 1, 5-bis(diphenylphosphino)pentane (dppp5) to the NiL4 catalyst is selected experimentally. Compared to the results obtained with NiL4 as catalyst, the (dppp5)NiL2 increases the conversion of 2M3BN from 74.5 % to 93.4 % at 3 h of reaction and provides a high selectivity to 3PN (> 98 %) at optimal conditions.
METHOD FOR PRODUCING 3-PENTENENITRILE
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Page/Page column 35-38; sheet 5, (2008/06/13)
The invention relates to a method for producing 3-pentenenitrile, said method being characterised by the following steps: (a) 1,3-butadiene is reacted with hydrogen cyanide on at least one catalyst to obtain a flow (1) containing 3-pentenenitrile, 2-methyl-3-butenenitrile, the at least one catalyst, and 1,3-butadiene; (b) the flow (1) is distilled in a column to obtain a top product flow (2) rich in 1,3-butadiene, and a bottom product flow (3) that is poor in 1,3-butadiene and contains 3-pentenenitrile, the at least one catalyst, and 2-methyl-3-butenenitrile; (c) the flow (3) is distilled in a column to obtain a top product flow (4) containing 1,3-butadiene, a flow (5) in a side-tap of the column, containing 3-pentenenitrile and 2-methyl-3-butenenitrile, and a bottom product flow (6) containing the at least one catalyst; and (d) the flow (5) is distilled to obtain a top product flow (7) containing 2-methyl-3-butenenitrile, and a bottom product flow (8) containing 3-pentenenitrile.
METHOD FOR PRODUCING LINEAR PENTENENITRILE
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Page/Page column 72-76; sheet 2, (2008/06/13)
The invention relates to a method for producing 3-pentenenitrile, characterised by the following steps: (a) isomerisation of an educt stream containing 2-methyl-3-butenenitrile on at least one dissolved or dispersed isomerisation catalyst to form a stream (1), which contains the isomerisation catalyst(s), 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z)-2-methyl-2-butenenitrile; (b) distillation of the stream (1) to obtain a stream (2) as the overhead product, which contains 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z)-2-methyl-2-butenenitrile and a stream (3) as the bottom product, which contains the isomerisation catalyst(s); (c) distillation of the stream (2) to obtain a stream (4) as the overhead product, which is enriched with (Z)-2-methyl-2-butenenitrile in comparison to stream (2), (in relation to the sum of all pentenenitriles in stream (2)) and a stream (5) as the bottom product, which is enriched with 3-pentenenitrile and 2-methyl-3-butenenitrile in comparison to stream (2), (in relation to the sum of all pentenenitriles in stream (2); (d) distillation of stream (5) to obtain a stream (6) as the bottom product, which contains 3-pentenenitrile and a stream (7) as the head product, which contains 2-methyl-3-butenenitrile.
