摘要 |
<p>A method for the preparation of a compound of formula (VI): in which R<SUB>2 </SUB>is an optionally substituted C1-C6 alkyl; R<SUB>4 </SUB>is H, OH, an optionally substituted C1-C6 alkyl or an optionally substituted C1-C6 alkoxy; R<SUB>5 </SUB>is an optionally substituted aryl, an optionally substituted aralkyl, or an optionally substituted alkyl; and R<SUB>6 </SUB>is H or an optionally substituted C1-C6 alkyl; the method including the step of subjecting a ketone of formula (V) in which R<SUB>2</SUB>, R<SUB>4 </SUB>and R<SUB>5 </SUB>are as defined above, to reductive amination with an amine of formula R<SUB>3</SUB>NH<SUB>2 </SUB>in which R<SUB>3 </SUB>is an optionally substituted alkyl, and a reductant to form the compound of formula (VI), wherein the reaction is conducted in the presence of a supercritical fluid or a liquefied gas.</p> |