See ref 9. 6 Lit.9 158-164°, uncrystallized. ' Lit.9 107-109°.hr, evaporation of this solution and treatment of the residue as above gave finally 0.27 g (2.8%) of the crystalline isomer le (mixture melting point, tic, and ir).(b) la (5.91 g, 0.03 mol) and PC15 (6.25 g, 0.03 mol) were mixed and heated at 160°for 30 min, then POCI3 was removed in vacuo, and the residue was triturated with a little CHCI3, collected, and crystallized (CeHe-CCD to give 4.55 g (70%) of 4-chloro-lH-2,3-benzothiazine 2,2-dioxide (11), mp 172-174°. Anal. (C8H6C1N02S)C,H, Cl, N, S.A suspension of 11 (3.23 g, 0.015 mol) in 2-PrOH (20 ml) was refluxed for 4 hr and the obtained solution let stand in the cold to complete separation of the product, that was collected, washed, dried, and recrystallized (2-PrOH) to afford 2.6 g (72%) of 10, mp 182-183°, identical (analysis, tic, mixture melting point, and ir) with the product described under (a). Supplementary Material Available. A listing of the pharmacological data for weakly active or inactive compounds will appear following these pages in the microfilm edition of this volume of the journal. Photocopies of the supplementary material from this paper only or microfiche (105 X 148 mm, 20X reduction, negatives) containing all of the supplementary material for the papers in this issue may be obtained from the Journals Department,
