Girards reagents T and

Girard s reagent P CsH5NCH2C0NHNH2 Cl. In a 1-litre threenecked flask, equipped as in the previous preparation, place 200 ml. of absolute ethyl alcohol, 63 g. (64 5 ml.) of pure anhydrous pyridine and 98 5 g. (84 5 ml.) of ethyl chloroacetate. Heat the mixture under reflux for 2-3 hours until the formation of the quaternary salt is complete acidify a small test-portion with dilute sulphuric acid it should dissolve completely and no odour of ethyl chloroacetate should be apparent. Cool the mixture in ice and salt. Replace the thermometer by a dropping funnel, and add a solution of 40 g. of 100 per cent, hydrazine hydrate in 50 ml. of absolute ethanol all at once. A vigorous exothermic reaction soon develops and is accompanied by vigorous effervescence. The product separates almost immediately. When cold, filter with suction, wash 

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The reagent is analogous to Girard reagents T and P and is prepared in the same way and used for isolation of a ketone from a mixture by conversion to a derivative extractible from ether with dilute hydrochloric acid. It is stated to be more easily purified than reagents T and P. 

GIRARD SANDULESCU Reagent Reagents T and "P" (or separation ol aldehydes or Ketones by brming a water soluble hydraaide derivative. 

Girard Reagent T (2-hydrazino-N,N,N-trimethyi-2-oxo-ethanaminium chioride) [123-46-6] M 167.6, m 192 . Should be crystd from absolute EtOH (slight decomposition) when it has a slight odour, and stored in tightly stoppered containers because it is hygroscopic. 

Other hydrazine derivatives frequently used to prepare the corresponding hydrazone are semicarbazide NH2NHCONH2, in which case the hydrazone is called a semicarbazone, and Girard s reagents T and P, in which case the hydrazone is water-soluble because of the ionic... 

The synthesis of ( )-7-ACA 81a is shown in Scheme 19. Reaction of 77 with 4-nitrobenzaldehyde followed by treatment with Hilnig s base gave a 2 3 mixture of cis/trans isomers of the Schiff base 79. Compound 79 was therefore cleaved with Girard s reagent T and amines 77 and 80 were obtained after chromatography. Amine 80 was converted to ( )-7-ACA 81a as outlined below. 

Reference Standards. Reference standards for TLC, GC, and MS were obtained as follows. Pure abietic acid (mp 172-173 °C) was used as received. Dehydroabietic acid was prepared by oxidation of abietic acid with selenium dioxide to hydroxy abietic acid and subsequent dehydration with glacial acetic acid (11). 7-Ketodehydroabietic acid was prepared by oxidation of dehydroabietic acid with potassium permanganate and isolation of the product by way of the Girard reagent T (12). Pyroabietic acid (a mixture of dehydro- and dihydroabietic acids) was prepared by heating abietic acid with 10% palladium on charcoal to 250 °C for 1 h (13). 

GIRARD SANDULESCU Reagent Reagents T and -P for separation of aldehydes or ketones by farming a water soluble hydrazide derivative. 

Water-soluble hydrazones are also provided by the Girard reagents P and T,524,929 which have proved their worth for separation of mixtures of natural products.930, 931 The condensation is usually effected in aqueous methanol buffered with acetate.524... 

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