Cyanoethyl

The last-named reaction provides an excellent method for the preparation of a-substituted glutaric acids the intermediate alkyl (aryl) -2-cyanoethyl-malonate is both hydrolysed and decarboxylated re ily by boiling with an excess of 48 per cent, hydrobromic acid solution. 

A widely used protecting agent is 2-cyanoethanol (- 3-hydroxypropanonitrile, hy-dracrylonitrile), which is condensed with phosphates with the aid of DCC. The 2-cyanoethyl (Ce) group is quantitatively removed as acrylonitrile by treatment with weak bases (H.G. Kho-rana, 1965). 

Because coupling is not always quantitative, the non-reacted terminal deoxynucteoside must be excluded from the following synthesis cycles. Otherwise deletion sequences will render the isolation of the pure final product difficult. Therefore a capping step (step 3) follows, e.g., acetylation with acetic anhydride and N,N-dimethyl-4-pyridinamine (DMAP) in dioxane. Capping times should be as short as possible, especially with 2-cyanoethyl phosphite triesters, which are sensitive to bases such as DMAP. 

Acrylonitrile reacts with the sodium salt of 4.5-dimethvl-A-4-thiazoline-2-thione (73J (R4 = R5 = Me) to yield 3-(2-cyanoethyl)-4.5-dimethyl-A-4-thiazoline-2-thione (74) (R4 = R, = Me) (Scheme 35 (160). Humphlett s studies of this reaction showed that the size of the R4 substituent is a determinant factor for the S versus N ratio (161. 162). If R4 == H, 100% of the N-substituted product (74) is obtained this drops to 50% when R4 = methyl, and only the S-substituted product (75) is obtained when R4 = phenyl. The same trend is observed with various CH2 = CH-X (X = C00CH3. COCH3) reagents (149). The S/N ratio also depends on the electrophilic center for CH2 = CH-X systems thus S-reaction occurs predominantly with acrylonitrile, whereas N-substitution predominates with methvlvinvlketone (149). 

THACRYLIC ACID AND DERIVATIVES] (Vol Id) N-(2-Cyanoethyl)-Nmethylmethacrylamide [7d392-04-d]... 

N- acetylmethacryl- amide /V-m eth a cry oylm al e- am ic acid methacryloylamido-acetonitrile N- (2-cyanoethyl)meth-acrylamide l-methacrjioylurea... 

N,N- dimethylmeth-acrylamide N,N- diethylmethacryl- amide N- (2-cyanoethyl)-A/-methylmethacrylami de... 

The 2-cyanoethyl group was cleaved from an aromatic sulfide with K2C03/NaBH4 (DMF, 135°, 70% yield). ... 

Methyl Carbamate 5. 9-Fluorenylmethyl Carbamate 8. 2,2,2-Trichloroethyl Carbamate 11. 2-Trimethylsilylethyl Carbamate 16. 1,1-Dimethylpropynyl Carbamate 20. 1-Methyl-1-phenylethyI Carbamate 22. 1-Methyl-l-(4-biphenylyl)ethyl Carbamate 24. 1,1 -Dimethy 1-2-haloethyl Carbamate 26. l,l-Dimethyl-2-cyanoethyl Carbamate 28. r-Butyl Carbamate... 

The submitters have found that other arylamines may be employed in a similar manner in place of aniline. Thus N-2-cyanoethyl-/)-anisidine was obtained in 76% yield as plates,... 

N-2-cyanoethylaniline has been prepared (accompanied by much of the N,N -bis-2-cyanoethyl compound) by heating aniline, acrylonitrile and acetic acid either in an autoclave, or at refluxing temperature for 10 hours in the presence of various inorganic catalysts. The substance has also been obtained, free of the N,N -bis-2-cyanoethyl compound, from aniline salts and /3-diethylaminopropionitrile. ... 

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