( R )-Baclofen [( R )-4-amino-3-(4-chloro-phen-yl)butanoic acid].

This article provides the first single-crystal XRD-based structure of enanti-opure ( R )-baclofen (form C), C10 H12 ClNO2 , without any co-crystallized substances. In the enanti-opure title compound, the mol-ecules arrange themselves in an ortho-rhom-bic crystal structure (space group P 21 21 21 ). In the crystal, strong hydrogen bonds and C-H⋯Cl bonds inter-connect the zwitterionic mol-ecules.