Hydroxamic acid derivatives and the method for preparing thereof
申请人:Rho Ho-Sik
公开号:US20060252834A1
公开(公告)日:2006-11-09
The present invention provides hydroxamic acid derivatives represented by the following formula (I), having anti-aging efficacy and a method for preparation thereof:
wherein,
R
1
is
herein, R
5
and R
6
each independently represents a hydrogen atom, a C
1
-C
10
alkyl group or a C
3
-C
6
cyclic alkyl group;
R
2
is CONH, NHCO, CONR
7
or NR
7
CO, herein, R
7
represents a C
1
-C
10
alkyl group;
R
3
is —(CH)
n
—, herein, n=0 or 1; and
R
4
is a hydrogen atom or a C
1
-C
10
alkyl group.
Further, the present invention provides skin-care external compositions for preventing skin aging, containing said hydroxamic acid derivatives represented by the formula (I) as an active ingredient.
Pivalic anhydride is shown to be an effective reagent for direct amidation of carboxylic acids with N-alkyl anilines. The only by-product of this reaction is nontoxic pivalic acid, which can be easily removed by aqueous workup. The reactions are conducted under mild conditions and found to be compatible with a range of carboxylic acids, including aromatic, heterocyclic, acrylic, and aliphatic carboxylic
Deprotection of amides is a virtually universal transformation in organic synthesis, often employing traditional active reductants such as SmI2, hydrosilanes, hydroboranes or H2 under high-pressure. Herein, we describe a green and sustainable electrocatalytic hydrolysis of amides utilizing water as the hydrogen source, thereby ideally avoiding the use of high-pressure and flammable hydrogen gas or