Carbamic acid, ethyl ester → HCID 178517462, compound

Participants

Reaction Conditions

Reaction Steps

100 g (2.4 mol) of sodium amide (95%) are stirred for 12 hours at room temperature in 500 ml of ®Dowtherm (mixture of 26.5% by weight of diphenyl and 73.5% by weight of diphenyl ether) in the presence of glass beads. The glass beads are then separated and washed with 500 ml of ®Dowtherm. The resultant suspension is heated to 90° C. and 232 g (2.35 mol) of benzonitrile are added dropwise over 1 hour such that the temperature does not rise above 105° C. Sniffing is continued for 3 hours at 95° C., then the reaction mixture is cooled to 15° C. and 260.4 g (2.4 mol) of ethyl chloroformate are added dropwise over 2 hours. The reaction mixture is then heated to 170° C. and the pressure is lowered to 150-80 mbar, whereupon 300 g of distillate consisting of ethanol, urethane and ®Dowtherm are distilled over. After a reaction time of 2 hours, the batch is cooled, filtered, and the filter residue is washed with 1 liter of methanol, giving 255.4 g of a white product of formula ##STR3##

Provenance & Evidence