Acetic Anhydride → Diethyl ((3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl)methyl)phosphonate

Participants

Reaction Conditions

Reaction Steps

A thermostatically controllable reactor is charged with 553.8 g (2.1 mol) of (4-hydroxy-3,5-di-tert-butylbenzyl)dimethylamine und 450 g of petroleum ether 100/140. With stirring and blanketing with inert gas, the reaction mixture is heated to 60° C. and 366.4 g (2.2 mol) of triethyl phosphite are run into the clear solution. With cooling, 225.1 g (2.2 mol) of acetic anhydride are then added dropwise over 2 hours at 60° C., and stirring is continued for 1 hour at 60° C. The solvent is removed by distillation until the temperature is 115° C. The residual reaction solution is washed with 4×250 ml of water at 75° C. and dried by azeotropic distillation. Upon cooling to room temperature, the product crystallises and is filtered with suction, washed with petroleum ether 100/140 and dried, giving 693.2 g (92.6% of theory) of colourless diethyl 4-hydroxy-3,5-di-tert-butylbenzylphosphonate of m.p. 119°-121° C.

Provenance & Evidence