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Benzoylation of 2a.-A solution of 2a (1 g, 0.00435 mol) and benzoyl chloride (1.4 g, 0.01 mol) in dry xylene (15 ml) was heated under reflux for 16 hr using a fiberglass heating mantle. The dark brown solution was diluted with benzene (10 ml), de-colorized with charcoal, and concentrated to dryness in a rotating evaporator under reduced pressure. The residual yellow oil (1.8 g) partially crystallized. Trituration with cold dry ether and collection at the filter gave 0.47 g (32% yield) of product, mp 145-150°. Recrystallization from methanol gave pure 10 (0.35 g, mp 158-160°) identical with the material obtained from, the pyrolysis of 2a. From the ethereal filtrate there was obtained an oil (0.47 g) which gave a colorless fraction (0.17 g) soluble in warm pentane. This oil could not be crystallized despite indications of virtual homogeneity by tic analysis. Although its infrared and mass spectra (M+ = 333.0339; caled for CnH^ChNCh: 333.0322) were nearly identical with the corresponding spectra of 10, the CHS singlet in the nmr appeared at 2.13 ppm instead of at 2.28 ppm for compound 10. Structure 12 for this oil was again ruled out by the following experiment.Benzoylation of 3a.-Application of the foregoing procedure to 1.31 g (0.0057 mol) of 3a gave a dark oil (1.8 g) that crystallized upon trituration with ether. Collection at the filter gave 1.05 g (mp 108-111°, 55% yield) of crude product. Several recrystallizations from methanol gave pure 0-benzoyl-A-(2,2dichloroisopropenyl)benzimidate ( 12): mp 111-113°; ir (CIICU) 1700 cm"1 (C=0), and no NH; nmr (CDC13) 8.3-7.3 (m, 10, ArH), and 2.13 ppm (s, 3, CHS).

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