Benz oxathiole

Beilstein Handbook Reference) BCG BRN 0372527 Bromcresol green EINECS 200-972-8 NSC 7817 Phenol, 4,4 - 1,1-dioxido-3H-2,1-benz-oxathiol-3-ylidene)bis(2,6-dibromo-3-methyl- Phenol, 4,4 -(3H-2,1-benzoxathiol-3-ylidene)bis(2,6-dibromo-3-methyl-, S,S-dioxide o-Toluenesulfonic acid, o-hydroxy-, gamma-sultone Tetrabromo-m-cresolphthalein sulibne. An acid indicator pH 3.8 (yellow)-5.4 (blue-green). Red-yellow crystals mp = 218.5° Xjn = 211, 278, 338,426 nm (e 54100. 8500, 7550, 17100 MeOH), 312, 394, 620 nm (s 13300, 8520, 40100 MeOH/KOH) insoluble in H2O, soluble in organic solvents. Lancaster Synthesis Co. Mallinckrodt Inc. Sigma-Aldrich Fine Chem. 

Double-Michael addition of various dinucleophiles l,2-(XH)(YH)CgH4 (X, Y = 0, S, NTs) to activated allenes R C=C=C(R )COR, giving rise to C(2)-functionalized benzimidazolines, benzoxazolines, benzothiazolines, 1,3-benzodioxoles, 1,3-benz-oxathioles, and 1,3-benzodithioles, respectively, can be facilitated by a catalytic amount of Me3P. Mechanistic studies unveiled the phosphine-triggered general base catalysis pathway. ... 

Lau and Gompf359 prepared a series of 2-amino-6-hydroxybenzo[d]-thiazoles and corresponding naphtho[l,2-d]thiazoles on treating 1,4-benzoquinone and 1,4-naphthoquinone with thiourea in acidic media at room temperature. At high temperature the products of the reaction with 1,4-benzoquinone are 5-hydroxy benz[d]-l,3-oxathiol-2-ones... 

With 1,4-naphthoquinones, the corresponding naphth-[2,l-d]-l,3-oxathiol-2-ones 207 are formed 362 whereas, with tetra-substituted thioureas and 1,4-benzoquinone, the benz[d]oxathiolium salts 208 are produced.363,364... 

In an approach relying on directed metalation, exposure of the functionalized benzamides 24 to LDA, and subsequent reactions of the resulting intermediates with aldehydes, provided the thioaurones 25 in good yields <05T9007>. An alternative thioaurone synthesis has been accomplished by treatment of 4-acetyl-2-oxo-benz[l,3]oxathiole derivatives with aldehydes in the presence of piperidine acetate in DMSO <05T8648>. 

---