N-Phenylglycine → Glycine, N-nitroso-N-phenyl-

The precursor N-nitrosophenylglycine was prepared according to the method described in Organic Syntheses, Coll. Vol. 5, p. 962 (1973); Vol. 45, p. 96 (1965). N-phenyl glycine (50 g) was dissolved in water (600 ml) with stirring, and the solution was cooled to below 0° C. in a salt/ice bath mixture. To this was slowly added a cooled solution of sodium nitrite (25 g) in water (150 ml) so that the temperature of the mixture never rose above 0° C. After addition was complete, the mixture was stirred below 0° C. for 40 minutes after which a red-brown solution was obtained with a small amount of brown solid residue. The residue was removed by filtering the solution under vacuum, and the clear liquid was decolorised by treating with charcoal (5 g) for 5 minutes. After filtering off the charcoal, the solution was cooled again and acidified with concentrated hydrochloric acid (50 ml), whereupon a slightly reddish-brown precipitate formed. The mixture was stirred for 10 minutes and then the precipitate was filtered off. This was allowed to dry in air to give a tan coloured powder (48 g).

1. temperaturethe solution was cooled to below 0° C. in a salt/ice bath mixture
2. additionAfter addition
3. stirringthe mixture was stirred below 0° C. for 40 minutes after which a red-brown solution
4. customwas obtained with a small amount of brown solid residue
5. customThe residue was removed
6. filtrationby filtering the solution under vacuum
7. additionby treating with charcoal (5 g) for 5 minutes
8. filtrationAfter filtering off the charcoal
9. temperaturethe solution was cooled again
10. customformed
11. stirringThe mixture was stirred for 10 minutes
12. filtrationthe precipitate was filtered off
13. customto dry in air

ORD record

ord-ce985272f1d84b93a4e9752b532c0efb

Source dataset

uspto-grants-2013_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08507570B2