2-Amino-2-methyl-1-propanol → 2-(4-Chloro-2-iodophenyl)-4,4-dimethyl-4,5-dihydrooxazole

Temperature

0 °C

To a solution of 4-chloro-2-iodobenzoic acid (10 g, 35.4 mmol) in dry dichloromethane (100 mL) was added DMF (4 drops) followed by addition of oxalyl chloride (4.65 mL, 53.1 mmol) drop wise at room temperature. The reaction mixture was stirred for 4 h then the solvent and excess reagents were evaporated by rotovap. The residue was dissolved in dry dichloromethane (80 mL), added a solution of 2-amino-2-methyl-1-propanol (7.9 g, 8.5 mL, 88.5 mmol) in dichloromethane (20 mL), and stirred at room temperature over night. The solvent was removed, the resulting residue was dissolved in ethyl acetate (200 mL), washed with water (100 mL), 1N HCl (3×100 mL), and brine (100 mL), dried over sodium sulfate, filtered and concentrated. The residue was dissolved in dry toluene (200 mL) and cooled to 0° C. Thionyl chloride (7.75 mL, 106.2 mmol) was added drop wise, stirred at 0° C. for 30 min, then room temperature for 3 h. The reaction mixture was diluted with ethyl acetate (400 mL) and poured into a stirred solution of saturated aqueous NaHCO3 (400 mL) portion wise (vigorous gas evolution). The two layers were separated and the aqueous layer was extracted with ethyl acetate. The combined organic phases were dried over sodium sulfate, filtered and concentrated. The residue was purified by column chromatography on silica gel (120 g column, 0% ethyl acetate in hexanes to 60% ethyl acetate in hexanes) to give product (10.5 g, 88%). NMR (CDCl3) δ 8.04 (d, J=2.0 Hz, 1H), 7.67 (brs, 1H), 7.39 (dd, J=9.7, 1.5 Hz, 1H), 4.25 (s, 2H), 1.48 (s, 6H); MS EI m/z 336 (M+H)+.

1. customthe solvent and excess reagents were evaporated by rotovap
2. dissolutionThe residue was dissolved in dry dichloromethane (80 mL)
3. stirringstirred at room temperature over night
4. customThe solvent was removed
5. dissolutionthe resulting residue was dissolved in ethyl acetate (200 mL)
6. washwashed with water (100 mL), 1N HCl (3×100 mL), and brine (100 mL)
7. dry with materialdried over sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated
10. dissolutionThe residue was dissolved in dry toluene (200 mL)
11. stirringstirred at 0° C. for 30 min
12. waitroom temperature for 3 h
13. customThe two layers were separated
14. extractionthe aqueous layer was extracted with ethyl acetate
15. dry with materialThe combined organic phases were dried over sodium sulfate
16. filtrationfiltered
17. concentrationconcentrated
18. customThe residue was purified by column chromatography on silica gel (120 g column, 0% ethyl acetate in hexanes to 60% ethyl acetate in hexanes)

ORD record

ord-8a1e7e26df8c4638b025e2600c94df67

Source dataset

uspto-grants-2012_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08106221B2