Thionyl Chloride → Benzyl-rac-{1-[[2-(o-fluorobenzoyl)-4-nitrophenyl]carbamoyl]butyl}carbamate

Beteiligte Stoffe

Reaktionsschritte

19.7 g of N-carbobenzoxy-DL-norleucine are dissolved in 200 ml of absolute tetrahydrofuran, the solution is treated dropwise while cooling with ice with 10 g of thionyl chloride and then stirred for 1 hour. To this solution there is rapidly added dropwise a solution of 17 g (0.065 M) of 2-amino-5-nitro-2'-fluorobenzophenone in 130 ml of absolute tetrahydrofuran and the mixture is then stirred at room temperature for 60 hours. The solution is concentrated and the residue is treated with ice and 10% sodium bicarbonate solution and extracted with methylene chloride. The organic solution is dried with sodium sulphate, filtered and concentrated. The residue is purified on a 450 g silica gel column using methylene chloride as the eluting agent and crystallised from ethanol. There is obtained benzyl-rac-{1-[[2-(o-fluorobenzoyl)-4-nitrophenyl]carbamoyl]butyl}carbamate which melts at 148°-150° C.

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