Mallinckrodt Specialty Chemicals Company

Other

John F Lang

Calvin E Kelly

Narayanasamy Gurusamy

Bromobiphenyls (such as 2-fluoro-4-bromobiphenyl) are synthesized by reacting together a phenylboronic acid (such as phenylboronic acid) and a bromoiodobenzene (such as 2-fluoro-4-bromoiodobenzene). The reaction generally takes place with the aid of a catalyst (such as palladium in a zero valance state) and an inert solvent (such as fluorobenzene). Control of temperature is very important to obtain both an acceptable reaction rate and an acceptable level of terphenyl byproduct.

Synthesis of bromobiphenyls

4-fluorobenzaldehydes are formed from compounds of the formula (I) ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are the same or different, and represent H, halogen, or an alkyl group of from 1 to about 10 carbon atoms, wherein, when at least one of R.sub.1, R.sub.2, R.sub.3 or R.sub.4 is halogen, at least one of remaining R.sub.1, R.sub.2, R.sub.3 or R.sub.4 is alkyl. the compound of formula of (I) is reacted with a formylating agent in the presence of FeCl.sub.3 in a reaction mixture, from which is separated a compound of the formula (II) ##STR2## wherein R.sub.1, R.sub.2 , R.sub.3 and R.sub.4 are as defined above.

Synthesis of fluorobenzaldehydes

A method and apparatus are disclosed for permanently marking a metal workpiece. The apparatus comprises a support for supporting the apparatus in contact with the workpiece. A stamp holding means adapted to receive a predetermined number of stamps engages the support and carries the stamps. The method comprises the steps of engaging the stamp holder with the support. Placing the support on the workpiece. Striking the stamps until the characters are at the desired depth and then removing the stamp holder from the workpiece.

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Webster Groves, MO, United States of America

John F Lang