Sodium benzenesulfinate, benzyl

A mixture of 500 ml. of absolute ethanol (p. 142), 178 g. (1.0 mole) of sodium benzenesulfinate (p. 27), and 127 g. (1.0 mole) of benzyl chloride is heated under reflux for 7-8 hours. The reaction mixture is then poured into 1 1. of ice water and the precipitated solid is removed by filtration. Recrystallization of the solid from ethanol gives 120 g. (52%) of sulfone, m.p. 146-146.5°. 

To a flask containing 178 gm (1 mole) of sodium benzenesulfinate is added 127 gm (1 mole) of benzyl chloride in 500 ml of absolute alcohol. The mixture is refluxed for 8 hr and the hot mixture is poured into 1 liter of ice water. The crude product is filtered, dried, and recrystallized from ethanol to give 120 gm (52%), mp 146°-146.5°C. 

Reaction of 2-chloromethyl-4//-pyrido[l,2-u]pyrimidine-4-one 162 with various nitronate anions (4 equiv) under phase-transfer conditions with BU4NOH in H2O and CH2CI2 under photo-stimulation gave 2-ethylenic derivatives 164 (01H(55)535). These alkenes 164 were formed by single electron transfer C-alkylation and base-promoted HNO2 elimination from 163. When the ethylenic derivative 164 (R = R ) was unsymmetrical, only the E isomer was isolated. Compound 162 was treated with S-nucleophiles (sodium salt of benzyl mercaptan and benzenesulfinic acid) and the lithium salt of 4-hydroxycoumarin to give compounds 165-167, respectively. 

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