Phosgene in pyridine

One of a variety of syntheses of the antipsychotic agent bro-foxine (50) begins with a Grignard reaction on methyl anthra-nilate. The resulting product ( ) is reacted with phosgene in pyridine and the synthesis is completed by bromination in acetic acid to give brofoxine. 

On the other hand, vV-aryl-//-nitrosoaminonitriles undergo interesting secondary reactions. Under acidic conditions, salts of the sydnonimes form (Eq. 13) under basic conditions, a rearrangement to an isomeric oxime takes place, which, on treatment with phosgene in pyridine leads to 4-substituted-3-cyano-l,2,4-oxadiazolinones (Eq. 14) [26b],... 

Three examples of the direct synthesis of intermolecular carbonates from carbohydrate derivatives by the action of phosgene in pyridine have been reported. Von Vargha condensed l,2 5,6-di-0-isopropylideue-D-glucofu-ranose with the calculated quantity of phosgene in a benzene-pyridine medium and selectively hydrolyzed the 5,6-0-isopropylidene group in the product XXXI with warm, 80% acetic acid, to give bis(1,2-0-isopropyli-... 

Cyclic carbonates [1, 857-858, after line 1], Plattner et al.na cited the reaction of a steroidal ctr-1,3-diol with phosgene in pyridine-chloroform to form a cyclic carbonate as evidence of the cis relationship of the groups. Another example is reported by Boulch, Raoul, and Ourisson.12b... 

The anhydrides 186 react with primary amines in alcohol and form compounds 187. The reaction of the latter with phosgene in pyridine (80°C) [104], in boiling benzene [109, 110], or in toluene (90°C) [111] leads to cyclization with the formation of 2,4-quinazolinedione derivatives 188 [104, 109-111],... 

Startg. glycol treated with phosgene in pyridine product. Y ca. Pfeiffer et al., Tetrah. Let. 1968, 3549. 

The first aromatic polycarbonates were prepared more than a century ago by reacting hydroquinone or resorcinol with phosgene in pyridine, but the crystalline polymers produced were brittle and difficult to process. After 50 years, a crosslinked resin was introduced, prepared by a free-radical polymerisation using a peroxide as initiator and an unsaturated carbonate derivative as a monomer. 

Alkyl-2-chloro- and -2-fluoro-sulphonylcarbamoyl chlorides (376), prepared simply from sulphamoyl halides RNHSO2X and phosgene in pyridine/ are useful precursors for the synthesis of 1,2,4,6-thiatriazine 1,1-dioxides, e.g. (377) and (378) (Scheme 85). ... 

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