Methylamine → 1H-Imidazole-4-carboxylic acid, 5-amino-1-methyl-, ethyl ester

Temperature

90 °C

A mixture of ethyl 3-nitriloalaninate (26.7 g, 208 mmol) and triethyl orthoformate (34.6 mL, 208 mmol) in 340 mL of acetonitrile is heated to 90° C. and stirred for 70 min. After cooling to RT, methylamine (25.9 mL of a 33 wt % solution in EtOH, 208 mmol) is added, followed by 20 h of stirring at RT. The reaction mixture is then concentrated in vacuo and dissolved in approx. 200 mL of 1N HCl. The aqueous solution is washed with CH2Cl2 (3×100 mL), basified to pH=9-10 with solid NaHCO3, and extracted with CH2Cl2 (5×100 mL). The combined CH2Cl2 extracts are dried (Na2SO4), filtered, and concentrated to give a brown solid. The solid is slurried in EtOAc, filtered, and washed with Et2O to give the title compound as an off-white solid. 1H NMR (400 MHz, CDCl3) δ 7.03 (1H, s), 4.88 (2H, bs), 4.33 (2H, q, J 7.2), 3.45 (3H, s), 1.37 (3H, t, J 7.2).

1. temperatureAfter cooling to RT
2. waitfollowed by 20 h
3. stirringof stirring at RT
4. concentrationThe reaction mixture is then concentrated in vacuo
5. dissolutiondissolved in approx. 200 mL of 1N HCl
6. washThe aqueous solution is washed with CH2Cl2 (3×100 mL)
7. extractionextracted with CH2Cl2 (5×100 mL)
8. dry with materialThe combined CH2Cl2 extracts are dried (Na2SO4)
9. filtrationfiltered
10. concentrationconcentrated
11. customto give a brown solid
12. filtrationfiltered
13. washwashed with Et2O

ORD record

ord-576244f62ad84fd8a15684156d68b8f9

Source dataset

uspto-grants-2014_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08759361B2