Substituted-Benzaldehydes

摘要

1,191,238. Substituted or unsubstituted benzoyl benzaldehydes. F. HOFFMANN-LA ROCHE & CO. A.G. 28 March, 1968 [30 March, 1967; 18 May, 1967], No. 28271/69. Divided out of 1,191,237. Heading C2C. Novel compounds of the general Formula I: wherein R1, R2, R3 and R4 individually represent a halogen atom or the trifluoromethyl or hydroxy group or a lower alkyl having 1 to 6 carbon atoms or lower alkoxy group having 1 to 6 carbon atoms and wherein the broken lines denote that the atoms or groups attached thereto are optional and the dots in the formula represent carbon atoms, are prepared by refluxing the corresponding substituted 2-hydroxymethylbenzhydrol in acetic acid with selenium dioxide or by adding the corresponding substituted benzoyl benzoic acid to lithium aluminium hydride in tetrahydrofuran and then treating with selenium dioxide under reflux. The compounds exemplified are o-benzoylbenzaldehyde, 2 - (4 - chloro - benzoyl) - benzaldehyde, 2 - (4 - methoxy - benzoyl) - benzaldehyde, 2 - benzoyl - 4 - chloro - benzaldehyde, 2 - (4 - bromo - benzoyl) - benzaldehyde, and 2 - (2 - chloro - benzoyl) - benzaldehyde. 2 - (2 - Chloro - benzoyl) - benzoic acid is obtained by adding 2-(2-amino-benzoyl)-benzoic acid to a mixture of sodium nitrite and concentrated sulphuric acid and then adding to a solution of cuprous chloride, sodium chloride, concentrated hydrochloric acid and water. 2 - Chloro - 21- hydroxymethyl - benzhydrol is obtained by treating 2 - chloro - (2 - chlorobenzoyl)-benzoic acid with lithium aluminium hydride in tetrahydrofuran.