ChemicalBook CAS DataBase List 2-Thiophenecarboxylic acid, 5-chloro-4-(4-chloro-1-methyl-1H-pyrazol-5-yl)-

2-Thiophenecarboxylic acid, 5-chloro-4-(4-chloro-1-methyl-1H-pyrazol-5-yl)- synthesis

6synthesis methods

Product Name:2-Thiophenecarboxylic acid, 5-chloro-4-(4-chloro-1-methyl-1H-pyrazol-5-yl)-
CAS Number:1047630-61-4
Molecular formula:C9H6Cl2N2O2S
Molecular Weight:277.13

1047630-52-3 Synthesis

2-Thiophenecarboxylic acid, 5-chloro-4-(1-methyl-1H-pyrazol-5-yl)-, methyl ester

1047630-52-3
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2-Thiophenecarboxylic acid, 5-chloro-4-(4-chloro-1-methyl-1H-pyrazol-5-yl)-

1047630-61-4
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Yield:1047630-61-4 48%

Reaction Conditions:

Stage #1: methyl 5-chloro-4-(1-methylpyrazol-5-yl)-2-thiophenecarboxylatewith N-chloro-succinimide in tetrahydrofuran at 70; for 4 h;
Stage #2: with sodium hydroxide in tetrahydrofuran;water; for 2 h;
Stage #3: with hydrogenchloride in water;

Steps:

96.a

To a 500 ml. flask was added methyl 5-chloro-4-(1 -methyl-1 H-pyrazol-5-yl)-2-thiophenecarboxylate (5 g, 19.48 mmol) [from Example 95] and NCS (3.12 g, 23.37 mmol) in tetrahydrofuran (THF) (100 ml) (50 ml_). After stirring for 4 h at 70 ⁰C, the yellow reaction solution was treated with 6M NaOH (32 ml_, 195 mmole) and stirred an additional 2 hours. The reaction solution was diluted with H₂O (50 ml.) and DCM (200 ml_). The organic layer was separated and the aqueous layer made acidic with 6N HCI. The acidic aqueous solution was extracted with DCM (3 x 200 ml_), dried over Na₂SO₄, and concentrated to give the crude product [2.6 g, 48%] as a tan solid: LCMS (ES) m/z 277 (M+H)⁺.

References:

WO2008/98104,2008,A1 Location in patent:Page/Page column 190

24065-33-6 Synthesis