| 摘要 |
<p>1,205,385. Amino-2-alkylcoumarans. FARBENFABRIKEN BAYER A.G. 5 March, 1969 [13 March, 1968], No. 11720/69. Heading C2C. Amino-2-alkylcoumarans of the formula wherein R represents a C 1-4 alkyl group, are prepared by reduction of benzofurans of the formula wherein R<SP>1</SP> represents an amino or nitro group, at 50-200‹ C. in an inert solvent under a pressure of 5-100 atmos. gauge over a Pd catalyst, the amount of Pd present being at least 1.3% by wt. based on benzofuran reactant. A Pd/charcoal catalyst is preferred. Specified solvents include alcohols and ethers. The catalyst may be regenerated by washing with solvent. The product may be isolated as an acid addition salt, eg. with HCl. Examples describe the preparation of 5- and 7-amino-2- methylcoumaran. Amino - 2 - alkylbenzofurans may be prepared by catalytic reduction, over Raney Ni, of the corresponding nitro-2-alkylaminobenzofurans.</p> |
