New coumarin derivatives, namely (2-(4-methyl-2-oxo-2H-chromen-7-yloxy)-N-(4-oxo-2-phenylthiazolidin-3-yl)acetamide, N-(2-(3-methoxyphenyl)-4-oxothiazolidin-3-yl)-2-(4-methyl-2-oxo-2H-chromen-7-yloxy)acetamide, 2-(4-methyl-2-oxo-2H-chromen-7-yloxy)-N-(4-oxo-2-(2,3,4trimethoxyphenyl)thiazolidin-3-yl)acetamide and N-(2-(4-bromophenyl)-4-oxothiazolidin-3-yl)-2-(4-methyl-2-oxo-2H-chromen-7-yloxy)ac...

The title compounds, rac-(1'R,2R)-tert-butyl 2-(1'-hydroxyethyl)-3-(2-nitrophenyl)-5-oxo-2,5-dihydro-1H-pyrrole-1-carboxylate, C(17)H(20)N(2)O(6), (I), rac-(1'S,2R)-tert-butyl 2-[1'-hydroxy-3'-(methoxycarbonyl)propyl]-3-(2-nitrophenyl)-5-oxo-2,5-dihydro-1H-pyrrole-1-carboxylate, C(20)H(24)N(2)O(8), (II), and rac-(1'S,2R)-tert-butyl 2-(4'-bromo-1'-hydroxybutyl)-5-oxo-2,5-dihydro-1H-pyrrole-1-car...

In the crystal structure of the title compound, C(10)H(6)N(2)O(6)·2H(2)O, the OH and NH groups each serve as a hydrogen-bond donor to one acceptor site whereas the water mol-ecules each serve as a hydrogen-bond donor to two acceptor sites. The hydrogen-bonding scheme gives rise to a three-dimensional network.