To a flask containing a solution of 136.0 gm (1.0 mole) of pentaerythritol in 1 liter of water (25-29°C) is added 5.0 ml of concentrated hydrochloric acid and then 106 gm (1.0 mole) of benzaldehyde is dropwise added (approx. 2 - 3 hr). The mixture is stirred for 3-5 hr and then the precipitated product is filtered, recrystallized from 1500 ml of slightly alkaline water ( N a 2C03) , filtered, and dried. The product is again recrystallized from toluene (1.3-1.5 liters) to afford 175 gm (80%), m.p. 133.5°C.
