2. The following compound is used to treat lung carcinomas. The drug inhibits a kinase by forming a covalent bond with a specific amino acid residue. The electrophilic portion of the drug is referred to as a 'warhead' NH a. The drug reacts by a conjugate addition reaction. Identify and circle the 'warhead'. b. Draw the electrophilic portion of the molecule (the warhead) and attach it to an R1 that represents the rest of the molecule. Use this representation for the next part. c. Assume the molecule reacts with a cysteine residue. Use R2SH to represent Cys and draw arrow pushing mechanism for the reaction between Cys and the warhead. d. Draw the final product.