Photochlorination toluene-2,4-diisocyanate

Jahnisch et al. used an IMM falling-film microreactor for photochlorination of toluene-2,4-diisocyanate [38] (see also Chapter 4.4.3.3, page 161). As a result of efficient mass transfer and photon penetration, chlorine radicals were well distributed throughout the entire film volume, improving selectivity (side chain versus aromatic ring chlorination by radical versus electrophilic mechanism) and spacetime-based yields of l-chloromethyl-2,4-diisocyanatobenzene compared to those obtained using a conventional batch reactor. 

The microstructured falling film reactor has also been used for chlorination reactions [77]. Chlorination of acetic acid at a temperature over 140 C was carried out and the by-product (dichloroacetic acid) was reduced significantly, meaning that there is no need for additional costly and time-consuming separation processes. Further, a photochemical gas-liquid reaction by the selective photochlorination of toluene-2,4-diisocyanate (TDl) was demonstrated [78]. 

Photochlorination of toluene-2, 4-diisocyanate (TDl) Falling film MSR Ehrich et al. [33]... 

Ehrich et al. investigated the photochlorination of the sidealkyl aromatic compound using the example of the conversion of toluene-2,4-diisocyanate (TDI) to l-chloromethyl-2,4-diisocyanatobenzene (ICl-TDI) [11]. The reaction product represents an important intermediate in the production of polyurethane. The ring chlorination to toluene-5-chloro-2,4-diisocyanate (5C1-TDI) occurs as a secondary reaction (Scheme 16.6). The main product and secondary product can react further to give high molecular weight resultant products. 

Toluene-5-chloro-2,4 disocyanate (5-CI-TD)] Scheme 16.6 Photochlorination of toluene-2,4-diisocyanate (TDI) to the target product lK hloromethyl-2,4-diisocyanatobenzene. As a secondary product toluene-S ihloro-2,4[Pg.449]

Selective fluorination of 4-nitrotoluene, 1,3-dicarbonyl, and heterocyclic compounds [46] Chlorination of acetic acid [47] Photochlorination of toluene 2,4-diisocyanate (TDI) [48]... 

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