Synthesis, crystal structure and hydrogen-bonding patterns in (RS)-1-carbamoyl pyrrolidine-2-carboxylic acid

The title compound, N-carbamoyl-DL-proline, C ₆H ₁₀N ₂O ₃, crystallizes in the triclinic P-1 space group with unit cell parameters a = 7.610 (4) Å, b = 9.259 (5) Å, c = 11.749 (7) Å, α = 110.294 (11)°, β = 101.304 (13)°, γ = 91.391 (16)°, with two crystallographically independent molecules in the asymmetric unit. The ureido and carboxyl groups are equatorial and axial to the pyrrolidine rings, respectively. The pyrrolidine rings adopt envelope and twisted conformations in the residue A and B, respectively. The molecules are joined by N-H...O and O-H...O hydrogen bonds into cyclic structures with graph set R ₂ ²(8), forming infinite chains parallel to the cb plane with graph set C ₂ ²(14), that are further connected via N-H...O hydrogen bonds into a three-dimensional network.