A scalable synthesis of a pyrimidine fungicide lead was developed. The pyrimidine head, 1-(5-bromopyridin-2-yl)-2,2-dimethyl-1-(pyrimidin-5-yl)propan-1-ol, was prepared by metal–halogen exchange of 2-iodo-5-bromopyridine with i-PrMgCl followed by treatment with pivaloyl chloride (PivCl) in the presence of CuCN·2LiCl and subsequent addition of 5-lithiopyrimidine. The boronic acid tail, (4-(1-cyanocyclobutyl)-2-fluorophenyl)boronic acid, was prepared via treatment of 1-(4-bromo-3-fluorophenyl)cyclobutane-1-carbonitrile with i-PrMgCl and trimethylborate. The o-fluoro Grignard reagent formed during this reaction sequence was analyzed by two-drop calorimetry and accelerating rate calorimetry, which revealed minimal safety concerns for scale-up. Finally, the boronic acid tail was coupled with the pyrimidine head in the presence of catalytic palladium acetate [Pd(OAc)2]/triphenylphosphine (PPh3) to deliver the final product in >95% yield after crystallization.