Yield:23821-99-0 65%

Reaction Conditions:

with Lawessons reagent in tetrahydrofuran; for 2 h;Reflux;

Steps:

7.1.2 4-Chloro-2-methoxythiobenzamide

Step 7-1-2
4-Chloro-2-methoxythiobenzamide
In tetrahydrofuran (100 ml), 4-chloro-2-methoxybenzamide (9.40 g, 50.6 mmol) prepared in the Step 7-1-1 and Lawesson's reagent (10.2 g, 25.3 mmol) were suspended, and the suspension was heated under reflux for 2 hours.
After the suspension was allowed to cool, a saturated sodium bicarbonate solution was added to the suspension to stop the reaction.
Then the reaction mixture was subjected to extraction with ethyl acetate, and the extract was dried over anhydrous magnesium sulfate and then concentrated.
The concentrate was purified by silica gel column chromatography (n-hexane:ethyl acetate=1:1) to give the title compound (6.63 g, 65%) as a yellow powder.
¹H-NMR (CDCl₃) δ: 8.89 (brs, 1H), 8.60 (d, J=8.5 Hz, 1H), 7.96 (brs, 1H), 7.04 (dd, J=1.9, 8.5 Hz, 1H), 6.95 (d, J=1.9 Hz, 1H), 3.97 (s, 3H)
Mass, m/z: 201&203 (M⁺), 168 (base)

References:

US2013/79306,2013,A1 Location in patent:Paragraph 0325; 0326; 0327; 0328