PURPOSE: To obtain a new isocyanate useful as an intermediate for separation agents having high optical resolution ability and enabling optical resolution of compounds which have not been able to be satisfactorily optically resolved when using conventional separation agents.
CONSTITUTION: This new isocyanate is 3-chloro-5-methylphenyl isocyanate of formula I, which is obtained by the following process: 5-nitro-O-toluidine is reacted with potassium chloride in hydrochloric acid to form a compound of formula II, which is reacted with concentrated sulfuric acid and sodium nitrite to eliminate the amino group to produce 3-chloro-5-nitrotoluene, then reacted with hydrochloric acid in the presence of tin to form 3-chloro-5-methylaniline, followed by reaction with phosgene by conventional method. 3-Chloro-5- methylphenyl carbamate derivative obtained by reaction of the compound of formula I with a polysaccharide is useful as a separation agent for optical resolution.
| JP2831808 | INDUSTRIAL APPLICABILITY [Title of Invention] Optical resolution method for racemic β-lactams |
| WO/1993/020110 | ESTERIFIED STARCH COMPOSITION |
| WO/2015/055741 | ACYLATION PROCESS |
YASHIMA EIJI
BEZAAN CHIYANKUBETAAZE
| JPS5780309A | 1982-05-19 | |||
| JPS6117555A | 1986-01-25 | |||
| JPS61233633A | 1986-10-17 | |||
| JPS63178101A | 1988-07-22 |