| 摘要 |
A process of preparing a benzamide derivative of the general formula: <FORM:0950281/C2/1> where R1 is an alkoxy or a monoalkylamino or dialkylamino radical and R2 is an alkyl radical comprises treating a compound of the general formula: <FORM:0950281/C2/2> with a base to open up the nitrogen-containing ring structure whilst at the same time substituting the >C = O grouping attached to the nitrogen and oxygen atoms in the ring structure by hydrogen and then alkylating the resultant compound to replace the hydrogen in the hydroxyl group by the alkyl radical R2. Bases specified include alkali hydroxides and carbonates and alkylamines. When alkylamines are employed the terminal radical is converted into an alkyl substituted amine radical. The alkylamines may be used in the forms of aqueous or alcoholic solutions. In examples N-2-methoxybenzoyl-N1, N1-dimethyl glycineamide is obtained by reacting 2, 4-dioxo-dihydro -1, 3-benzoxazinyl -(3)- acetate with aqueous dimethylamine to obtain N-2-hydroxy-benzoyl -N1 N1-dimethyl glycineamide which is treated with sodium and methyl sulphate (1); similar processes are carried using ethyl 2, 4-dioxodihydro-1, 3-benzoxazinyl -(3)- acetate and 2, 4-dioxodihydro-1, 3-benzoxazinyl -(3)-acetodimethylamide as starting materials (2, 3) whilst similar processes to (3) are carried out using aqueous sodium hydroxide and potassium carbonate instead of aqueous dimethylamine (4, 5). The starting materials for use in the process may be prepared by reacting 2, 4-dioxodihydro-1, 3-benzoxazine, preferably in the form of its alkali metal salt with a compound of the formula Z(CH2)nCOR where Z denotes halogen. Specification 858,426 is referred to. |
