反应 #2314318

反应方程式

Triphosgene

4-fluoroanthranilic acid

potassium carbonate

→

Methyl 4-Fluoroanthranilate Hydrochloride

溶剂

1,4-dioxane

反应条件

后处理

1. 1
   workup.WAIT50° C. for ca. 30 min
2. 2
   其他Solvent was removed in vacuo, dry methanol (30 ml)
3. 3
   workup.ADDITIONadded
4. 4
   workup.STIRRINGThe mixture was stirred at r.t. for 30 min
5. 5
   其他2.5 h
6. 6
   其他at 50° C
7. 7
   过滤Inorganic material was filtered off
8. 8
   萃取Aqueous layer was extracted with ethyl acetate (2×50 ml)
9. 9
   洗涤Combined organic layers were washed with water diluted aq. sodium bicarbonate (pH ca. 8; 2×50 ml), brine (50 ml)
10. 10
    干燥dried (MgSO4)
11. 11
    浓缩The organic solution was concentrated in vacuo (to ca. 75 ml), and 1 M hydrogen chloride in ethyl ether (ca. 25 ml)
12. 12
    workup.ADDITIONadded
13. 13
    过滤The precipitated crystalline product was filtered off
14. 14
    洗涤washed with ethyl ether, hexanes
15. 15
    其他dried in vacuo

实验过程

Triphosgene (3.26 g, 11 mmol) was added to 4-fluoroanthranilic acid (1.55 g, 1.0 mmol) in dry 1,4-dioxane (50 ml), and the mixture was stirred at rt. for 1 h, and then 50° C. for ca. 30 min. Solvent was removed in vacuo, dry methanol (30 ml) added, followed by potassium carbonate (4.42 g, 35 mmol). The mixture was stirred at r.t. for 30 min, and then 2.5 h at 50° C. Inorganic material was filtered off, and the residue distributed between ethyl acetate (150 ml) and the pH 7 buffer (75 ml). Aqueous layer was extracted with ethyl acetate (2×50 ml). Combined organic layers were washed with water diluted aq. sodium bicarbonate (pH ca. 8; 2×50 ml), brine (50 ml), and dried (MgSO4). The organic solution was concentrated in vacuo (to ca. 75 ml), and 1 M hydrogen chloride in ethyl ether (ca. 25 ml) added. The precipitated crystalline product was filtered off, washed with ethyl ether, hexanes, and dried in vacuo. Yield 1.00 g (49%). 1H NMR in 5% CD3OD in CDCl3 (δ, ppm): 3.83 (s, 3 H), 6.55 (m, 1 H), 6.66 (m, 1 H), 7.88 (m, 1 H).

来源