Borohydride Reduction

John Heger CMY 211 Lab Section 13 11-30-2011 Borohydride Reduction of Vanillin to Vanillyl alcoholic drink Introduction The usage of this research laboratory was to go down vanillin to vanillyl alcohol. This lab c everyplace recaps the procedure and results of the lab. The chemical process analyse in this lab was reduction, the process of reduction the issuance of bonds to group O and increasing the number of bonds to hydrogen. Other chemical processes included in the lab were recrystallization, liquescent depute, and extraction.Procedure Preparation of Vanillyl alcoholic drink 2. 5 mmol of vanillin were dissolved in 2. 5 mL of 1 M NaOH declaration in a 25 mL Erlenmeyer flask. The flask was swirled to produce a equal yellow solution. The flask was swirled in an ice-water lav for 1-2 proceeding and the solution was cooled to approximately 10C. 1. 95 mmol of NaBH4 was added while the solution was evermore swirled. It was added in three to four portions over a period of 3 minutes. The solution was allowed to stand undisturbed for 30 minutes at room temperature.After the time period, the flask was cooled in an ice-water bath and 3 M HCl was added dropwise with swirling. HCl was added until the pH of the solution was distinctly acrid to pH paper. The solution was gently cooled and the face of the flask was gently scratched with a starter rod to induce recrystallization. The crude overlap was suction filtered using a Buchner or Hirsch funnel and was washed with three minuscular portions of cold water. The crystals were allowed to air dry for several(prenominal) minutes while suction keep to eliminate excess water.The crude harvest was recrystallized from ethyl acetate. The dried crystals were weighed and a dissolve meridian was obtained. Results Table 1 data-based Data Table Initial mickle of Vanillin 0. 3843 g Final Mass of Vanillyl Alcohol 0. 2467 g Melting Point scat of Vanillyl Alcohol 75-90C Percent hold 63. 99 % yield Discussion Th e take aim of this lab was to reduce vanillin to vanillyl alcohol. The mechanism of the lab voluminous reduction. Sodium borohydride was used to reduce the aldehyde on the vanillin molecule, which left the oxygen with a negative charge.Feature Article sex act RatesFree-Radical BrominationHCl then reacted with the negative oxygen on vanillin, and the oxygen then became protonated, which make another alcohol on the benzene ring. The melting point range obtained for vanillyl alcohol was between 75-90C. The actual melting point was 115C, which was approximately 25 degrees high than the experimental values. The reason for this melting point difference can be attributed to impurities that create throughout the procedure. The percent yield from the pilot film sample was 63. 9%. A graceful percentage of the authentic sample was wooly throughout the reduction process of vanillin to vanillyl alcohol. completion Vanillin was reduced to vanillyl alcohol which obtained a melting point of 75-90C. The percent yield from the original sample was 63. 99%. The mechanism involved the reduction of vanillin to vanillyl alcohol, which increased the number of bonds to hydrogen and decreased the number of bonds to oxygen by the reduction of a carbonyl.