Ethyl Acetate → HCID 70408791, compound

Participants

Reaction Steps

A dispersion of NaH in oil (27.3 mmol) was weighed into a 11 round bottom flask containing a magnetic stirrer. The dispersion was washed with hexane to remove the mineral oil, and the flask was immediately charged with tetrahydrofuran (THF) (200 ml). Boc-2,6-dimethyltyrosine methylester (Example 29, 8 g, 24.8 mmol) was added and a drying tube was inserted The mixture was stirred for 2 hr. α-Bromo-p-toluonitrile (5.24 g, 26.8 mmol) was then added, and the mixture stirred at room temperature overnight. A thin layer chromotogram (2:1 Skelly B: Ethyl Acetate) was then run. If starting material was still present, NaH dispersion (1/2 molar amount) and alkylating agent (1/2 molar amount) were added and the reaction run another 24 hr at room temperature. The mixture was then poured into water (1.21) and rapidly extracted thrice with CH2Cl2. The organic fractions were combined, dried (MgSO4), and stripped to give a product (O-(p-cyanobenzyl)-Boc-2,6-dimethyltyrosine methyl ester) which was directly hydrolyzed with NaOH as described in Example 1 to give the title compound. NMR: benzyl methylene ∫5.10 s; tyrosyl aromatic protons ∫6.60s; benzyl aromatic protons centered at ∫7.65.

Provenance & Evidence