Cyanogen Bromide → N-(2,2-diethoxyethyl)carbodiimide

A solution of the aminoacetaldehyde diethyl acetal (13.16 g, 99 mmol) in ether (35 mL) was added to a suspension of CNBr (10.47 g, 99 mmol) in hexane (35 mL) at room temperature. The reaction mixture was stirred at room temperature overnight. The solid was removed by filtration and washed with ether. The combined filtrate was concentrated. Purification by column chromatography (silica gel, eluting with dichloromethane to 4% methanol in dichloromethane, gradient) afforded the title compound (7.0 g, 44.7%, one half of the starting amine served as a sacrificial base in the reaction) (Rf: 2.70, 4% methanol in dichloromethane, stain with 10% ethanolic molybdatophosphoric acid). 1H NMR 400 MHz (CDCl3) δ 4.58 (t, J=5.2 Hz, 1H), 3.77-3.69 (m, 2H), 3.65 (br, s, 1H), 3.60-352 (m, 2H), 3.16 (t, J=5.6 Hz, 1H), 1.23 (t, 6H, J=6.8 Hz).

1. customThe solid was removed by filtration
2. washwashed with ether
3. concentrationThe combined filtrate was concentrated
4. customPurification
5. washby column chromatography (silica gel, eluting with dichloromethane to 4% methanol in dichloromethane, gradient)

ORD record

ord-e93b9a0c21c24898bc8244a2c8cb2fea

Source dataset

uspto-grants-2010_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07745437B2