2-Cyan-1 -

Methoxy-3-oxo-2,3-diphenyl-1-(4-cyan-phenyl)- 872 l-Methoxy-.7-oxo-2,3-diphenyl-l-(4-inethoxycarbonyl-phenyl)- 872... 

Finally a general approach to synthesize A -pyrrolines must be mentioned. This is tl acid-catalyzed (NH4CI or catalytic amounts of HBr) and thermally (150°C) induced tea rangement of cyclopropyl imines. These educts may be obtained from commercial cyan> acetate, cyclopropyl cyanide, or benzyl cyanide derivatives by the routes outlined below. Tl rearrangement is reminiscent of the rearrangement of 1-silyloxy-l-vinylcyclopropancs (p. 7 83) but since it is acid-catalyzed it occurs at much lower temperatures. A -Pyrrolines constitut reactive enamines and may be used in further addition reactions such as the Robinson anei lation with methyl vinyl ketone (R.V. Stevens, 1967, 1968, 1971). 

Indol-2-ylcopper reagents can also be prepared from 2-lithioindoles and they have some potential for the preparation of 2-substituted indoles. 1-Methyl-indol-2-ylcopper can be prepared by reaction of 2-lithio-l-methylindole with CuBr[10]. It reacts with aryl iodides to give 2-aryl-1-methylindoles. Mixed cyanocuprate reagents can be prepared using CuCN[ll], The cyan-ocuprate from 1-methylindole reacts with allyl bromide to give 2-allyl-l-methylindole. 

Cyanacryl Cyanagel Cyanamer Cyan amide Cyanamide [420-04-2]... 

Cyanamide flush Cyan amides Cyanate Cyanazine... 

Cyan dyes Cyan ex 272 Cyanex 301 Cyanex 302 Cyanex 921 Cyanex 923 Cyanex 925... 

Hydroxy-2-Naphthalenecarboxylic Acid. l-Hydroxy-2-naphthoic acid is made similarly to the isomer (2-hydroxy-1-naphthoic acid) by reaction of dry sodium 1-naphthalenolate with CO2 in an autoclave at ca 125°C. It has been used in making triphenylmethane dyes and metalli able a2o dyes. Alkylamides and arylamides of l-hydroxy-2-naphthalenecarboxyhc acid are cyan couplers, ie, components used in indoaniline dye formation in color films (see Color PHOTOGRAPHY). 

Printers use colored materials, eg, inks (qv), that absorb or subtract regions of the visible spectmm from white light. Subtractive color is usually represented by the three printer s primaries cyan, magenta, and yeUow (CMY). Cyan absorbs red light, magenta absorbs green, and yeUow absorbs blue light. 

Color contamination is another factor that needs to be considered. For example, a small amount of cyan commonly contaminates magenta. Thus, adding magenta to color-correct an image also adds cyan, which must be removed for compensation. 

Instmments like colorimeters and spectrophotometers are used less often. These ate used primarily for manufacturing control of printing inks. Ftequentiy, however, inks other than yellow, magenta, and cyan ate used for spot-color appHcations, and in those instances a spectrophotometer ensures the correct match of an ink blend to standard. 

Fig. 10. In each image-forming layer, developer oxidi2ed by the exposed silver haUde (Dev ) reacts with the appropriate coupler to form the corresponding subtractive primary dye, yellow, cyan, or magenta. Ar represents an aryl group and the various R s are undefined organic segments.

Fig. 13. Cyan dye-forming couplers where X can be H, Cl, OAr, OR, or SAr. Ar is aryl. R and R are undefined organic segments.

Some cyan dyes derived from both naphthols and phenols are reported to show thermochromism, a reversible shift in the dye hue as a function of temperature. This can occur in a negative while prints are being made (65). 

Fig. 14. Masking coupler used in the cyan layer showing (—) the unwanted density to blue-green light that accompanies cyan dye formation matched by (- --) a complementary density to blue-green from the unreacted coupler, and (— — ) density to red light.

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