Dimethylmalonic acid → N-(4-methylthiophenyl)-2,2-dimethylmalonamic acid

Thionyl chloride (8.15 g, 5 ml, 0.069 mol) was added to a stirred solution of 2,2-dimethylmalonic acid (7.26 g, 0.055 mol) in dry THF (55 ml). The mixture was heated under reflux for 3 hr. The reaction mixture was cooled to room temperature and 4-methylthioaniline (15.3 g, 0.11 mol) in THF (30 ml) was then added dropwise over 30 mins to the solution. The mixture was stirred at room temperature for 2 hr. The reaction mixture was then concentrated in vacuo and then treated with hydrochloric acid (2N, 100 ml). The product was extracted with ethyl acetate (2×100 ml). The organic extracts were combined, then washed with water (100 ml) and saturated sodium hydrogen carbonate solution (5×80 ml). The organic layer was then acidified with hydrochloric acid (5N, 250 ml) and the resultant white crystalline precipitate was collected by filtration to afford N-(4-methylthiophenyl)-2,2-dimethylmalonamic acid. mp 130-132° C.

1. temperatureThe mixture was heated
2. temperatureunder reflux for 3 hr
3. concentrationThe reaction mixture was then concentrated in vacuo
4. additiontreated with hydrochloric acid (2N, 100 ml)
5. extractionThe product was extracted with ethyl acetate (2×100 ml)
6. washwashed with water (100 ml) and saturated sodium hydrogen carbonate solution (5×80 ml)
7. filtrationthe resultant white crystalline precipitate was collected by filtration

ORD-Eintrag

ord-46c241adb70544f493479d5acc0f2e7b

Quelldatensatz

uspto-grants-2005_01

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06844338B2