天堂网亚洲,天天操天天搞,91视频高清,菠萝蜜视频在线观看入口,美女视频性感美女视频,95丝袜美女视频国产,超高清美女视频图片

Welcome to chemicalbook!
Chinese English Japanese Germany Korea
400-158-6606
Try our best to find the right business for you.
Do not miss inquiry messages Please log in to view all inquiry messages.

Welcome back!

ChemicalBook CAS DataBase List ANTHRANILIC ACID, N-BOC-5-HYDROXY
244765-00-2

ANTHRANILIC ACID, N-BOC-5-HYDROXY synthesis

2synthesis methods
-

Yield:244765-00-2 92.5%

Reaction Conditions:

with phosphoric acid;sodium carbonate in tetrahydrofuran;

Steps:

1.A A.

A. N-Boc-5-hydroxyanthranilic acid [1] 5-Hydroxyanthranilic acid (100 g, 0.65 mol) was transferred into a 5 liter 3-necked round bottom flask equipped with a mechanical stirrer. A solution of saturated sodium carbonate (1.5 liters) was added to the reaction flask with stirring. After carbon dioxide evolution had subsided, di-t-butyldicarbonate (156.8 g, 0.72 mol) in 1.5 liters of tetrahydrofuran (THF) was added to the reaction vessel which was stirred at a rate which insured complete mixing of the resulting biphasic mixture. The reaction mixture was stirred at room temperature for 24 hours at which time 1.0 liters of ethyl ether was added and the mixture transferred to a separatory funnel. The aqueous layer was extracted with an additional 1.0 liters of ethyl ether and brought to pH=3.0 with 2 M H3PO4. Product was extracted from the aqueous solution with ethyl acetate (3*1.0 liters). The combined organics were washed with a saturated NaCl solution, dried over Na2SO4, filtered and concentrated in vacuo to yield N-Boc-5-hydroxyanthranilic acid (153 g, 92.5% yield).

References:

US6171578,2001,B2

ANTHRANILIC ACID, N-BOC-5-HYDROXY Related Search: