Rivaara Labs Research Associate Interview Questions and Answers

Seeking new challenges and opportunities for growth.

• Desire for new challenges and opportunities for growth

• Seeking a more stimulating work environment

• Looking to expand skill set and knowledge

• Company restructuring or downsizing

• Relocation to a new area

Selective reduction of acid in presence of ester

• Use a reducing agent that selectively reduces acid over ester

• Common reducing agents are LiAlH4 and NaBH4

• LiAlH4 reduces both acid and ester, but in presence of acid it selectively reduces acid

• NaBH4 reduces only acid, not ester

• Example: Reduction of benzoic acid to benzyl alcohol in presence of benzyl ester using LiAlH4

BuLi reagent is a highly reactive and pyrophoric compound used in organic synthesis.

• BuLi should be handled under an inert atmosphere, such as nitrogen or argon.

• It should be stored in a dry and cool place, away from water and air.

• BuLi should be added slowly to the reaction mixture, with constant stirring.

• Personal protective equipment, such as gloves and goggles, should be worn at all times.

• In case of fire, use a Class D...read more

Reagents used in Suzuki coupling

• Palladium catalyst (e.g. Pd(PPh3)4)

• Organoboron compound (e.g. arylboronic acid)

• Base (e.g. potassium carbonate)

• Solvent (e.g. DMF, toluene)

Rest ethyl acetate in compound can be found by NMR using specific peaks and chemical shifts.

• Look for the peak at 1.0-1.2 ppm which corresponds to the ethyl group

• Look for the peak at 4.0-4.1 ppm which corresponds to the acetate group

• Subtract the integral of these peaks from the total integral to find the rest ethyl acetate

• Compare the chemical shifts of the peaks to known values for ethyl acetate