This article presents the structure of the organic chemistry laboratory Course "Synthesis and Extraction of Drugs" that is included in Modena University (Italy) in the third year of the five-year "Chemistry and Pharmaceutical Technologies" degree program. This course is unique in its kind, and it aims to provide students with the critical-thinking skills required to face practical organic synthesis. Because the "problem-based learning" approach ensures a high level of learning, we modified this approach to reconcile the students' knowledge, the resources available compared with the number of students, and the purpose of a deep learning. Accordingly, tailored academic materials have been prepared (a textbook, a laboratory notebook, and a selection of primary literature), appropriate in-class and laboratory activities have been set up, and a grading pattern that promotes the active learning process has been defined. Although the number of students is high, following this approach, very positive results with respect to both laboratory techniques and critical thinking ability have been obtained.