Transformation of β‐oxoesters with PhI(OCOCF3)2 leads to α‐(ortho‐iodophenyl)‐β‐oxoesters. These materials are the starting point for the synthesis of 6‐carboxybenzo[b]azocin‐2‐ones by a sequence of aryl amination and ring transformation. This reaction sequence starts with copper‐catalyzed formation of N‐alkyl anilines from the iodoarenes and primary amines in the presence of K3PO4 as stoichiometric base. The intermediate products underwent ring transformation by addition of the nitrogen into the carbonyl group of the cycloalkanone, furnishing benzo‐annulated eight‐membered ring lactams. Under the same reaction conditions, the cyclohexanone and cycloheptanone derivatives gave no aminated products, but ring‐transformed to benzofuran derivatives. The title compounds of this investigation contain two points for further diversification (the lactam nitrogen and the carboxylate function), thus, the suitability of this compound class as a scaffold was proven by appropriate functionalizations. The first series of derivatizations of the scaffold was initiated by hydrogenolytic debenzylation of N‐benzyl derivative to provide the NH‐congener, which could be deprotonated with LDA and alkylated at nitrogen to give further examples of this compound class. Secondly, the ester function was submitted to saponification and the resulting carboxylic acid could be amidated using HATU as coupling reagent to furnish different amides.
Direct extraction of high purity ethanol from fermentation broth was investigated using a vacuum fractionation technique. Batch and repeated-batch extractive fermentation of ethanol were carried out using concentrated sweet sorghum as a carbon source. The effect of product inhibition was reduced by continuous removing ethanol from the fermented broth. About 60 % relative viability was observed in fermented broth with a higher productivity value. Due to the high value of living cells presented in the medium, repeated-batch extractive fermentation was subsequently performed. The ethanol was continuously fractionated out from the system at the average rate of 10.2 g/h with the concentration of approximately 80 wt%. There were 8 cycles of fermentation using only 1 time inoculation. Nevertheless, the calculated ethanol productivity and relative viability for each fermentation cycle were decreased gradually due to the accumulation of toxic substances in fermented broth. The simulation of 200 liters continuous extractive fermentation system using ASPEN PLUS was studied including process optimization and economical consideration. 18.5 liters of ethanol solutions 82 wt% with insignificant amounts of by-product was produced from a 200 liters extractive fermentation system per day. Production cost including raw material and utilities cost was approximately 0.71 €/liter. The economic and systemic performance process were subsequently analyzed, and including that ethanol loss was recovered using a gas scrubber connected to the vapor exiting the venturi tank as well as in the stillage stream. The calculated utility costs after process modification were 0.5 €/liter of ethanol, approximately 30 % of production cost was reduced.
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