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
010-86108875
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 2-Acetyl-5-bromothiophene
5370-25-2

2-Acetyl-5-bromothiophene synthesis

10synthesis methods
2-Acetylthiophene

88-15-3

2-Acetyl-5-bromothiophene

5370-25-2

The general procedure for the synthesis of 2-acetyl-5-bromothiophene from 2-acetylthiophene was as follows: 2-acetylthiophene (1.08 mL, 10 mmol), N-bromosuccinimide (NBS) (1.78 g, 30 mmol), and acetic anhydride (3.78 mL, 40 mmol) were added sequentially to a dry, 25 mL round-bottomed flask, which was equipped with a protective tube. Acetic acid (0.40 mL) was subsequently added to the mixture. The reaction mixture was stirred at 50 °C for 1 h protected from light and the color of the solution was observed to change from colorless to light yellow. Upon completion of the reaction, the mixture was cooled to room temperature and poured into 100 mL of water with continuous stirring until the acetic anhydride was completely hydrolyzed. At this point, 2-acetyl-5-bromothiophene precipitated as white crystals. The product was collected by filtration and washed in batches with 50 mL of water to give a final yield of 82%. The melting point of the product was 92-94 °C (acetone).1H NMR (300 MHz, CDCl3) data were as follows: δ 7.40 (d, J=3.9 Hz, 1H), 7.08 (d, J=3.9 Hz, 1H), 2.48 (s, 3H).

-

Yield:5370-25-2 86.1%

Reaction Conditions:

in dichloromethane

Steps:

R.1 2-Acetyl-5-bromothiophene (b-1) STR41
REFERENTIAL EXAMPLE 1 2-Acetyl-5-bromothiophene (b-1) STR41 When 1.56 ml (1.1 equivalents) of acetyl chloride was added to a solution of 3.26 g (0.02 mmol) of 2-bromothiophene in 30 ml of CH2 Cl2, the mixture foamed and turned black. After stirring for 1 hr. at room temperature, the mixture was mixed with ice and concentrated hydrochloric acid. While being decolored with active carbon, the mixture was extracted with CH2 Cl2, whereby 3.53 g (Yield: 86.1%) of the objective product, 2-acetyl-5-bromothiophene (b-1) was obtained as colorless crystals.

References:

Shinogi & Co., Ltd. US4839365, 1989, A

FullText

2-Acetyl-5-bromothiophene Related Search: