Abstract: A one pot process for the preparation of sterically hindered triaryl phosphite is provided. The triaryl phosphite is of the formula P(OR)3 and is produced by reacting a hydroxyl-substituted aryl compound of formula ROH with phosphorus trihalide in a presence of a Lewis base, wherein R represents an aryl compound of a formula C6H3R1R2, wherein each R1 and R2 is an organic substituent. The process preferably comprises of mixing a substantial stoichiometric amount of 2,4-dialkyl phenol with phosphorous trihalide in methylene chloride with stoichiometric amount of pyridine. The reaction is preferably carried out at 0-5° C. and takes only 1 hr for the completion, followed by a precipitation out of isopropanol.