重氮化反应 氨基变巯基.pdfVIP

Organic Syntheses, Coll. Vol. 2, p.580 (1943); Vol. 12, p.76 (1932). THIOSALICYLIC ACID [Benzoic acid, o-mercapto-] Submitted by C. F. H. Allen and D. D. MacKay. Checked by Roger Adams and A. E. Knauf. 1. Procedure Caution! Recently it was reported to us that workers, following the procedure in Coll. Vol. II, pg 580 (diazotization of anthranilic acid and its reaction with sodium disulfide) but substituting 2,3- dimethylaniline for anthranilic acid, experienced a serious explosion upon addition of the diazonium salt solution to the disulfide solution. We urge that extreme caution should always be exercised in the handling of diazonium salts even when they are in solution. In a 4-l. beaker, 290 cc. of water is heated to boiling, and 260 g. (1.1 moles) of crystallized sodium sulfide (Na S·9H O) and 34 g. of powdered sulfur are dissolved by heating and stirring. A solution of 40 2 2 g. of sodium hydroxide in 100 cc. of water is then added and the mixture cooled, first in cold water, and finally by a freezing mixture of ice and salt. In a 2-l. beaker, set in a freezing mixture and provided with a stirrer and a thermometer for reading temperatures to 0°, are placed 500 cc. of water, 137 g. (1 mole) of anthranilic acid, and 200 cc. of concentrated hydrochloric acid; the stirrer is started and the mixture cooled to about 6°. Meanwhile 69 g. (1 mole) of sodium nitrite is dissolved in 280 cc. of hot water and the solution cooled in ice; portions are then placed in a separatory funnel of convenient size, supported in such a way that the lower end of the stem extends beneath the surface of the anthranilic acid solution. When the temperature has fallen to 5°, the nitrite solution is run in; about 500 g. of cracke