Reference

Chemical safety

Chemical safety. The instability of azides. Burns, Michael E.; Smith, Richard H., Jr. (Environ. Control Res. Program, Natl. Cancer Inst., Frederick, MD, USA). Chem. Eng. News, 62(2), 2 (English) 1984. CODEN: CENEAR. ISSN: 0009-2347. DOCUMENT TYPE: Journal CA Section: 59 (Air Pollution and Industrial Hygiene) Section cross-reference(s): 23 An accidental explosion that occurred during synthesis of Me azide (I) [624-90-8] from Me2SO4 [77-78-1] and sodium azide [26628-22-8] is described. The explosion is attributed to the formation of hydrazoic acid [7782-79-8] during a 1-h reaction. Although a NaOH soln. was added dropwise, the addn. rate was probably insufficient to maintain the soln. at a pH of >7. A decrease in pH to 5 is known to cause an explosion. In subsequent prepns. of I, an indicator, bromothymol blue (II) [76-59-5], was added to the flask. This indicator changes color from deep blue to light yellow over the pH range 6.5-8.0 and thereby provides a rapid visual warning of pH drop. Addnl. indicator can be added when the color fades. The addn. of II does not affect the yield of I.

Distribution of ion pairs of sympathomimetic amines and a sulfophthalein derivative

Distribution of ion pairs of sympathomimetic amines and a sulfophthalein derivative. Hernandez, A.; Gutierrez, P.; Thomas, J. (Dep. Fisicoquim., Fac. Farm., Granada, Spain). Cienc. Ind. Farm., 2(7-8), 255-60 (Spanish) 1983. CODEN: CIDFA8. ISSN: 0210-0819. DOCUMENT TYPE: Journal CA Section: 63 (Pharmaceuticals) Section cross-reference(s): 64 Five sympathomimetic amines, i.c. ephedrine [299-42-3], bamethan [3703-79-5], ethylphenylephrine [10128-36-6], phenylephrine [59-42-7], and metaproterenol [586-06-1] formed blue ion pairs in the presence of bromothymol blue [76-59-5]. These ion pairs were extd. by CHCl3. The extn. const. of the ion pairs was directly correlated to the size of the amine mol. and inversely correlated with the no. of OH phenolic groups.