Page 170 - CW E-Magazine (12-3-2024)

Special Report

used a chlorinated high temperature sta- (LTO) is reacted with aqueous HBr to F. Ferretti et al have derived an epoxy
ble cationic Ion Exchange Resin (IER) give the 3-bromo LT and in the second from C and applied in the development
catalyst, which leads to signifi cant cost step aqueous alkaline hydrolysis allows of a Vitrimer system. This work uses a
reduction. Feeding crude MeOH has -Br to -OH and this uses CuI catalyst to diboronic ester thiol ((2,2’-(1,4-pheny-
advantages from cost view point. Reactive give LD. The overall yield was close to lene)-bis(4-mercaptan-1,3,2-dioxaboro-
distillation was adopted and with these 42%. This process looks attractive. (Org. lane), DBEDT) as a cross-linker and no
measures a substantial reduction in cost Proc. Res. Dev., 2023; DOI: 10.1021/ solvents are used and no catalyst through
is realised to the extent of 39%. (Re- acs.oprd.3c00313). a thiol-epoxy “click” mechanism. The
action Chem. Eng., 2023; DOI: 10.1039/ developed material is easily biodegrad-
D3RE00333G). Process development for the able in sea water and has a promising
manufacture of the anti-mala- fl ame reaction behaviour. This material
A novel process towards the rial, Amodiaquine dihydrochlo- has some additional attributes. (ACS
industrial realisation of large- ride dihydrate (ADHDH) Omega, 2023, DOI 10.1021/acsomega.
scale oxymethylene dimethyl 3c07459).
ether (OMDME) production – M. Gohain et al have reported a robust
COMET process for ADHDH, which required On the role of surfactants:
three steps that involves a Mannich
F. Mantei et al have referred to the pro- reaction, substitution with 4,7-dichlo- rethinking “aqueous” chemistry
mising solubility and combustion proper roquinoline (DCQ) and rehydration. B.H. Lipshutz has covered some of
ties of various chemical processes and A process for DCQ is also reported the latest technological developments
sectors. Clean and quasi soot-free com- starting with meta-chloroaniline. (Org. involving chemistry in water. Nature has
bustion is realised, leading to consider- Proc. Res. Dev., 2023; DOI: 10.1021/ secrets to guide us. There are obvious
able NOx emission reduction. It seems acs.oprd.3c00205). advantages in using water, rather than
only the production based on OMDME organic solvents; reactions takes place
and trioxane can be demonstrated and Green and low-cost synthesis usually inside the micellar core. Also,
of thermally stable cation water-insoluble substrates are solu-
exchange resin supported diazo- bilised due to micelles. (Green Chem.,
2023, DOI 10.1039/D3GC 03875K).
nium salt; process for weakly
basic p-nitroaniline (PNA) Formation of N-Nitrosamines
diazotisation (NN) by reaction of secondary

F. Liu et al have worked on the title dialkylamine with trace levels
scaled up, but it is complex and energy- process where thermal stability and of nitrite in aqueous solution;
intensive. The novel COMET (Clean explosive hazards are encountered. These an automated experimental and
OMDME) process concept is introduced authors have used Amberlyst 15 to make kinetics modelling using di-n-
and experimentally demonstrated and the corresponding diazonium salt of butyl amine.
this depends solely on methanol and weakly basic PNA. The synthesis con- [The presence of NN has made a big
formalin as feedstock and overcomes the ditions were optimised. The yield was impact in the sale of tartans and other
challenging water management aspect. up to 80%. The process involves a good drugs and this column has covered some
The scale of production is at 100,000- storage stability. (Org. Proc. Res. Dev., papers.]
tpa. Electrolytic H and CO are consi- 2023; DOI: 1031021/acs.oprd.3c00301).
2
2
dered for MeOH. (Reaction Chem. Eng.,
2023; DOI: 10.1039/D3RE00147D). On a bio-based epoxy vitrimer S. Diab et al have reported the kinetic
modelling of the title reactions leading
Scalable and cost-effective syn- from a cardanol (C) derivative to the presence of NN. They have iden-
thetic process for the prepara- prepared by a simple thiol – tifi ed conditions which present the risk
tion of L-3,4-dimethoxyphenyl- epoxy “click” reaction of the formation of NN. An important
alanine – Levo-Dopa (LD) [There is an increasing emphasis on conclusion is that a signifi cant risk in
using renewable raw materials and the use solutions is at pH less than 6 and higher
LD is a well-known drug and R. Goura of C, a by-product of cashew cultivations concentrations of nitrite. (Org. Proc.
et al have given a facile process, which which has a phenolic OH, for making Res. Dev., 2023; DOI: 10.1021/acs.
involves two simple steps. L-Tyrosine epoxy resins.] oprd.3c00404).

170 Chemical Weekly March 12, 2024

Contents Index to Advertisers Index to Products Advertised