5 - Iodo-2´-deoxyuridine ( 10.2 g , 28.9 mmol ) was co - evaporated with distilled pyridine ( 3 x 10 mL ) and dissolved in distilled pyridine ( 80 mL ) . To this was added drop - wise a solution of DMTCl ( 9.79 g , 28.9 mmol ) in distilled pyridine ( 50 mL ) over a period of 20 min and the reaction was stirred at rt for 3 h. An additional 0.2 eq DMTCl was added and the reaction stirred for a further 2.5 h. The reaction was quenched by the addition of MeOH ( 80 mL ) and was stirred for 20 min . Characterisation data recorded matches previously reported literature values ( 11 ) .