2-Amino-2-methyl-1-propanol → 2-(2,4-Dimethoxy-phenyl)-4,4-dimethyl-4,5-dihydro-oxazole

A solution of 27.4 g of 2,4-dimethoxybenzoyl chloride in 30 ml of methylene chloride was added dropwise to a solution of 26.2 g of 2-amino-2-methyl-1-propanol in methylene chloride at 0° C. The mixture was allowed to warm to room temperature and stirred overnight. The mixture was filtered and the filtrate washed twice with 1N hydrochloric acid, once with water, dried, and concentrated in vacuo. Excess thionyl chloride was added to the oily residue. After stirring one hour the mixture was poured into diethyl ether. The resulting solid was recovered by filtration and washed with diethyl ether. The solid was added to 1N sodium hydroxide and stirred. The aqueous mixture was extracted with ethyl acetate and the organic layer separated, dried, and concentrated in vacuo. Distillation of the resulting yellow oil at 165°-170° C. at 0.02 mm pressure provided 17.8 g of the desired subtitled intermediate.

1. filtrationThe mixture was filtered
2. washthe filtrate washed twice with 1N hydrochloric acid, once with water
3. customdried
4. concentrationconcentrated in vacuo
5. additionExcess thionyl chloride was added to the oily residue
6. stirringAfter stirring one hour the mixture
7. additionwas poured into diethyl ether
8. filtrationThe resulting solid was recovered by filtration
9. washwashed with diethyl ether
10. additionThe solid was added to 1N sodium hydroxide
11. stirringstirred
12. extractionThe aqueous mixture was extracted with ethyl acetate
13. customthe organic layer separated
14. customdried
15. concentrationconcentrated in vacuo
16. distillationDistillation of the resulting yellow oil at 165°-170° C. at 0.02 mm pressure

ORD record

ord-28a3f8df2a3040ff999e078c77d74f65

Source dataset

uspto-grants-1991_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04996230