1,2-Dibromoethane → HCID 145805292, compound

Participants

Reaction Steps

The starting material was prepared as follows. Using the procedure of Footnote 15, ethyl 2-((Z)-2-bromoethoxyimino)-2-(2-tritylaminothiazol-4-yl)acetate was prepared from 1,2-dibromoethane, and reacted with sodium azide in DMF solution. Purification by chromatography gave ethyl 2-((Z)-2-azidoethoxyimino)-2-(2-tritylaminothiazol-4-yl)acetate, which was dissolved in 1,2-dimethoxyethane and hydrogenated using 5% w/w palladium on charcoal as catalyst at ambient temperature and pressure for 16 hours. Catalyst was filtered off, and the solution was treated with bis(O-t-butyl)carbonic anhydride at ambient temperature. After 48 hours, the reaction was worked up conventionally, and the product isolated by chromatography on silica, eluting with 60:40 -l v/v hexane: EtOAc. The ethyl ester was saponified (see Footnote 15) to give 2-((Z)-2-t-butoxycarbonylaminoethoxyimino)-2-(2-tritylaminothiazol-4-yl)acetic acid, having the following n.m.r. in CDCl3 :-1.33(s, 9H; 3.37(m, 2H); 4.27(t, 2H); 5.38(br s, 1H); 6.59(s, 1H); s, 1H); 7.29 (m, 16H).

Provenance & Evidence