C3-Alkylation of furfural derivatives by continuous flow homogeneous catalysis

• Grédy Kiala Kinkutu,
• Catherine Louis,
• Myriam Roy,
• Juliette Blanchard and
• Julie Oble

Beilstein J. Org. Chem. 2023, 19, 582–592, doi:10.3762/bjoc.19.43

• File 1, p. S8). All the content of the loop is thus sent into the reactor. This system is coupled to a gas chromatography oven, in which the stainless-steel tubular reactor (length: 4.6 m, internal diameter of 0.8 millimeter, corresponding to a volume of 2.31 mL) is placed. The system pressure is

High-speed C–H chlorination of ethylene carbonate using a new photoflow setup

• Takayoshi Kasakado,
• Takahide Fukuyama,
• Tomohiro Nakagawa,
• Shinji Taguchi and
• Ilhyong Ryu

Beilstein J. Org. Chem. 2022, 18, 152–158, doi:10.3762/bjoc.18.16

• 10). This is due to the extended residence time from 15 to 30 s. Flow gas/liquid reactions are often carried out using a tubular reactor and mixer under slug flow conditions. However, it is not easy to apply such conditions to the present photochlorination reaction since the volume of the Cl2 gas is

• ca. 400 times larger than that of ethylene carbonate (for entry 8 in Table 1). In addition, a much longer tubular reactor would be required to ensure 15–30 s residence time. We then investigated the effect of contamination with water on the reaction, since Cl2 gas is known to react with H2O under

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

• process for the synthesis of β-methylionones (83) in flow. Tubular reactors were employed for the preparation and the two steps were reported separately (Scheme 15). The NaOH-catalysed condensation is performed in a 160 L tubular reactor with a 4 minutes residence time at 132 °C. The initial reaction

• mixture is biphasic, and a preliminary separation is carried out before entering the reactor coil. After discontinuous purification procedures, the product 82 was yielded in 98% purity (72% yield). The second step, instead, is an acid-catalysed cyclisation which employs the same tubular reactor at lower

Dawn of a new era in industrial photochemistry: the scale-up of micro- and mesostructured photoreactors

• Emine Kayahan,
• Mathias Jacobs,
• Leen Braeken,
• Leen C.J. Thomassen,
• Simon Kuhn,
• Tom van Gerven and
• M. Enis Leblebici

Beilstein J. Org. Chem. 2020, 16, 2484–2504, doi:10.3762/bjoc.16.202

• the particle to the wavelength of the light is called the size parameter. The scattering phenomenon in a tubular reactor is depicted in Figure 7. The efficiency of the absorption in scattering media with respect to pure absorption situations is shown in Figure 8. The optical thickness is the natural

Disposable cartridge concept for the on-demand synthesis of turbo Grignards, Knochel–Hauser amides, and magnesium alkoxides

• Mateo Berton,
• Kevin Sheehan,
• Andrea Adamo and
• D. Tyler McQuade

Beilstein J. Org. Chem. 2020, 16, 1343–1356, doi:10.3762/bjoc.16.115

• . System setup: The internal diameter of the perfluorinated tubular reactor used on the ODR prototype was limited to 6.3 mm to maintain an efficient heat transfer. Due to this ID limitation and the heater dimensions, we decided to separate Mg and LiCl in two tubular reactors. First, the concentration

A general and atom-efficient continuous-flow approach to prepare amines, amides and imines via reactive N-chloramines

• Katherine E. Jolley,
• Michael R. Chapman and
• A. John Blacker

Beilstein J. Org. Chem. 2018, 14, 2220–2228, doi:10.3762/bjoc.14.196

• phase-transfer catalyst was recently reported [25]. We have published a communication that describes the continuous mixing of aqueous NaOCl and an organic solution of secondary amine, using either a tubular reactor with in-line static mixers or a single stage CSTR [26]. The reactor was selected to

Assessing the possibilities of designing a unified multistep continuous flow synthesis platform

• Mrityunjay K. Sharma,
• Roopashri B. Acharya,
• Chinmay A. Shukla and
• Amol A. Kulkarni

Beilstein J. Org. Chem. 2018, 14, 1917–1936, doi:10.3762/bjoc.14.166

• dissolved in a THF and hydrazine was dissolved in a mixture of solvents such as methanol, acetone, and water. The nitrile was pumped using pump P1 and hydrazine was pumped through P2 into the tubular reactor TR1 maintained at a temperature of 130 °C at residence time of 60 minutes to obtain the pyrazole

• separator enters into the tubular reactor TR3 at a temperature of 20–40 °C with a residence time of 4 hours. Into this reactor nitrogen gas was pumped through peristaltic pump P7 and formic acid using pump P8. In TR3 gas–liquid reaction takes place. Formation of the lactate salt: In step four, lactic acid

• interconnected. The first, reactor module includes different reactors types that are commonly used in the synthesis of APIs viz. tubular reactor (R1–R4), packed bed reactor (R5–R8) and stirred tank reactor (R9). The reactors are equipped with a jacket for maintaining the reaction temperatures. Additionally

Automating multistep flow synthesis: approach and challenges in integrating chemistry, machines and logic

• Chinmay A. Shukla and
• Amol A. Kulkarni

Beilstein J. Org. Chem. 2017, 13, 960–987, doi:10.3762/bjoc.13.97

• tubular reactor with 1 min residence time at 25 °C in DMSO medium. This resulted in quantitative yield. The amide synthesis is carried out simultaneously by mixing methyl propiolate (1.5 equiv) and aqueous ammonia (6 equiv) solution in a T-mixer followed by a coiled reactor. The authors report over 95

• and one separation step. In the first step, a Friedel–Crafts acylation of isobutylbenzene (1 equiv) and propionyl chloride (1.17 equiv) in the presence of AlCl3 as Lewis acid was carried out in a tubular reactor. The residence time is one minute, and the temperature is maintained at 87 °C. The outlet

• and carried further saponification of the ester intermediate in another tubular reactor at 90 °C and 1 min residence time. The entire process is carried out at 200 psi pressure and the yield of the target product ibuprofen is reported to be 83%. This report has been among the most eye-popping works in

Self-optimisation and model-based design of experiments for developing a C–H activation flow process

• Alexander Echtermeyer,
• Yehia Amar,
• Jacek Zakrzewski and
• Alexei Lapkin

Beilstein J. Org. Chem. 2017, 13, 150–163, doi:10.3762/bjoc.13.18

• , see Figure 2. The reaction mixture segments and the solvent were pumped through a 10 mL polytetrafluoroethylene (PTFE) tubular reactor and quenched in an ice bath at the reactor outlet. A minimum segment volume of 2 mL was found to be necessary to avoid dispersion effects in the centre of the segment

Diels–Alder reactions of myrcene using intensified continuous-flow reactors

• Christian H. Hornung,
• Miguel Á. Álvarez-Diéguez,
• Thomas M. Kohl and
• John Tsanaktsidis

Beilstein J. Org. Chem. 2017, 13, 120–126, doi:10.3762/bjoc.13.15

• : 40 min; photographic images of a tubular reactor coil of the Vapourtec R2/R4 flow reactor [26] and of the plate reactor module of the Chemtrix Plantrix® MR260 [27]. Diels–Alder reaction of myrcene (1), with various dienophiles 2. Reagents, reaction conditions and results for small scale batch

A flow reactor setup for photochemistry of biphasic gas/liquid reactions

• Josef Schachtner,
• Patrick Bayer and
• Axel Jacobi von Wangelin

Beilstein J. Org. Chem. 2016, 12, 1798–1811, doi:10.3762/bjoc.12.170

• distributions (plug flow, bubbly flow, annular flow or isolated gas and liquid segments) can occur under certain conditions (Scheme 3, Figure 6) [67]. The formation of a steady slug flow can be best achieved in a long tubular reactor which leads to very efficient irradiation (Figure 6). Mixing of liquid phase

• and gas phase occurs upstream in a T mixer, while the tubular reactor should provide a high surface area for maximum exposure to the light source. For reaction times in the range of 10 s to 20 min, commercial fluorinated ethylene-propylene (FEP)-capillaries with an internal diameter of less than 1 mm

Continuous formation of N-chloro-N,N-dialkylamine solutions in well-mixed meso-scale flow reactors

• A. John Blacker and
• Katherine E. Jolley

Beilstein J. Org. Chem. 2015, 11, 2408–2417, doi:10.3762/bjoc.11.262

• solutions of N,N-dialkyl-N-chloramines is described using either a bespoke meso-scale tubular reactor with static mixers or a continuous stirred tank reactor. Both reactors promote the efficient mixing of a biphasic solution of N,N-dialkylamine in organic solvent, and aqueous sodium hypochlorite to achieve

• employed in this work, with increased surface area-to-volume ratio, allows effective heat dissipation under ambient conditions. Continuous reactor A nylon/PTFE tubular reactor was constructed that incorporates static mixers for enhanced mixing of the biphasic reaction solution, made of the acetal

• is generated should be used directly, so is ideally coupled with a second flow process, and the results of this will be reported elsewhere. Conclusion The facile synthesis of N,N-dialkyl-N-chloramines is described using either a tubular reactor with static mixers or a continuous stirred tank reactor

The synthesis of active pharmaceutical ingredients (APIs) using continuous flow chemistry

• Marcus Baumann and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2015, 11, 1194–1219, doi:10.3762/bjoc.11.134

• processed is directed into a tubular reactor which contains periodically spaced annular baffles thereby creating a series of eddies through oscillatory motion simultaneously applied to the reactor (Figure 2) [46]. The resulting vigorous axial and radial mixing results in very sharp residence time

• POCl3 were mixed in a simple Teflon T-piece before entering a tubular reactor maintained at 22 °C (4.5 mL, tres = 30 s). Upon exiting this reactor the crude stream of the Vilsmeier reagent 76 was combined with a stream of amide 80 in DMF that was prepared in situ in a batch reactor from proline amide

• precatalyst (85, 0.025 mol %, and Josiphos ligand 86) before being mixed with hydrogen gas and entering a plug flow tubular reactor (volume 1.46 or 73 L, hydrogen pressure 70 bar, 70 °C, residence time 12 h). Several campaigns were run over periods of several days (e.g., campaign 1: 282 hours total cumulative

Continuous flow nitration in miniaturized devices

• Amol A. Kulkarni

Beilstein J. Org. Chem. 2014, 10, 405–424, doi:10.3762/bjoc.10.38

• acid; microreactors; tubular reactor; Review 1 Introduction Nitration of aromatics is one of the oldest and industrially most important reactions. A reaction between an organic compound and a nitrating agent leads to the introduction of a nitro group onto a carbon, nitrogen or oxygen atom of that

• , nitric acid and acetic anhydride, which led to a homogeneous system. However, an over-oxidation of 16 was encountered due to the presence of acetic anhydride, so that benzoic acid was formed. The poor solubility of benzoic acid in the aqueous phase led to an immediate clogging of the tubular reactor

• approaches were tested. In the first approach, the reactants were continuously mixed by using a T-mixer followed by a tubular reactor maintained at a constant temperature (10–15 °C). Hydrolysis was carried out with ice water (~20 mol per mol of the reactant). The usage of a single tube facilitated a higher

Simple and rapid hydrogenation of p-nitrophenol with aqueous formic acid in catalytic flow reactors

• Rahat Javaid,
• Shin-ichiro Kawasaki,
• Akira Suzuki and
• Toshishige M. Suzuki

Beilstein J. Org. Chem. 2013, 9, 1156–1163, doi:10.3762/bjoc.9.129

• was reduced via hydrogen transfer from formic acid to p-nitrophenol and not by hydrogen generated by dehydrogenation of formic acid. Keywords: catalytic tubular reactor; flow chemistry; formic acid; hydrogenation; p-aminophenol; p-nitrophenol; Introduction The flow reaction process enables

• mass transfer resistance and therefore ensure a smooth flow of reactants without causing an undesirable pressure drop or clogging of reactor tubes. In addition, the tubular reactor offers a large surface-to-volume ratio, good mixing and heat-transfer properties that enhance the reaction rate [5]. We

• simple and efficient methodology to coat the inner wall of a tubular reactor with various thin metal layers. Aside from the plating of a single Pd layer, we examined co-plating of Pd and Ag from their 9:1 (atomic ratio) mixed solution, as depicted in Figure 1a. Metal ions in the plating solution are

Continuous preparation of carbon-nanotube-supported platinum catalysts in a flow reactor directly heated by electric current

• Alicja Schlange,
• Antonio Rodolfo dos Santos,
• Ulrich Kunz and
• Thomas Turek

Beilstein J. Org. Chem. 2011, 7, 1412–1420, doi:10.3762/bjoc.7.165

• process for the production of highly active Pt catalysts supported by carbon nanotubes by use of an electrically heated tubular reactor. The synthesized catalysts show a high degree of dispersion and narrow distributions of cluster sizes. In comparison to catalysts synthesized by the conventional oil-bath

• not cost intensive, because all components used for the construction are standard laboratory equipment. Using the continuously operated tubular reactor, heating rates comparable to a microwave oven were achieved. Furthermore, the preparation technique is supposed to have a great potential also for the

• with ethanol. Finally it was separated by means of a centrifuge at 4000 rpm and dried in an oven. Catalysts and support material characterization Thermogravimetric analysis (TGA) curves for pristine CNT, oxidized CNT, Pt/CNT oil bath and one of the Pt/CNT tubular reactor samples are given in Figure 3

Flow through reactors for organic chemistry: directly electrically heated tubular mini reactors as an enabling technology for organic synthesis

• Ulrich Kunz and
• Thomas Turek

Beilstein J. Org. Chem. 2009, 5, No. 70, doi:10.3762/bjoc.5.70

• nearly constant feed concentrations. The simplest ways to do this are to lower the residence time in the continuously operated tubular reactor by using a higher flow rate or the dilution of the reaction mixture by a solvent. Conclusion and Outlook A simple system was used for heating continuously

Radical carbonylations using a continuous microflow system

• Takahide Fukuyama,
• Md. Taifur Rahman,
• Naoya Kamata and
• Ilhyong Ryu

Beilstein J. Org. Chem. 2009, 5, No. 34, doi:10.3762/bjoc.5.34

• tubular reactor (internal diameter: 1000 μm), acting as the residence time unit (RTU), under heated conditions using an oil bath. A back pressure control valve was connected at the end of the RTU to regulate and maintain the pressure of the reactor system. Reaction time was adjusted via the flow rates of