SYNTHESIS AND CRYSTAL-STRUCTURE OF 1-ACETYL-3-BROMO-3-PHENYLAZETIDINEAND 1-PHENYL-2-(N-ACETYL-N-FORMYL)-AMINOETHANONE

1-Acetyl-3-bromo-3-phenylazetidine (1), C11H12BrNO, has been synthesiz ed and characterized by spectroscopic methods and single crystal X-ray analysis. It crystallizes in the space group P2(1)/c with a = 8.633(1 ), b = 7.461(1), c = 17.204(1) Angstrom, beta = 98.403(7)degrees, V = 1096.2(2) Angstrom(3), Z = 4, D-calc = 1.540 g cm(-3). The azetidine r ing is nearly planar since the four atoms are within +/-0.039(5) Angst rom of the mean square plane calculated for the heterocycle. The attem pt to obtain a highly strained 2-azetine derivative from the above com pound gave, surprisingly, 1-phenyl-2-(N-acetyi-N-formyl)-aminoethanone (2), C11H11NO3. This compound has been also characterized by spectros copic methods and single crystal X-ray analysis. It crystallizes in th e space group P2(1)2(1)2(1), with a = 5.4719(3), b = 8.3205(6), c = 23 .298(3) Angstrom, V = 1060.7(2) Angstrom(3), Z = 4, D-calc = 1.286 g c m(-3). The aminoethanone residue is in a near planar conformation wher e the torsion angles are 7(2)degrees for N-C-C=O and -173(2)degrees fo r N-C-C-C(Ph).