Formyl decomposition

A. l-Formyl-3-thiosemicarbazide. Four hundred milliliters of 90% formic acid contained in a 2-1. round-bottomed flask is heated on a steam bath for 15 minutes, and then 182 g. (2 moles) of colorless thiosemicarbazide (Note 1) is added. The mixture is swirled until the thiosemicarbazide dissolves. The heating is continued for 30 minutes, during which time crystalline 1-formyl-3-thiosemicarbazide usually separates. Boiling water (600 ml.) is added, and the milky solution that results is filtered through a fluted filter paper. After standing for 1 hour, the filtrate is cooled in an ice bath for 2 hours, and the l-formyl-3-thiosemicarbazide that separates is collected by suction filtration and air-dried overnight. It weighs 170 192 g. (71-81%) and melts at 177-178° with decomposition. 

Formylation of the amino aldehyde, and subsequent treatment of the amide (46) with ammonia enabled Armarego to prepare pyrido[2,3-d]pyrimidine (1). This compound was also obtained by the decomposition of the tosylhydrazino compound (47). ... 

Bimolecular decomposition of a non-metal hydride organometallic complex, such as metal formyl complexes, which may involve metal hydride precursors MC( = 0)H + H20 <-> M(CO)+ + OH + H2 N/A 36... 

The primary products are methyl and formyl radicals [36, 37] because potential energy surface crossing leads to a H shift at combustion temperatures [35], It is rather interesting that the decomposition of cyclic ethylene oxide proceeds through a route in which it isomerizes to acetaldehyde and readily dissociates into CH3 and HCO. Thus two primary addition reactions that can be written are... 

Anticipated products from the reaction of sym-dichloromethyl ether with ozone or OH radicals in the atmosphere, excluding the decomposition products formaldehyde and HCl, are chloromethyl formate and formyl chloride (Cupitt, 1980). 

In words, we describe the process as initiated by the decomposition of acetaldehyde to form the methyl radical CH3 and the formyl radical CHO. Then methyl attacks the parent molecule acetaldehyde and abstracts an H atom to form methane and leave the acetyl radical CH3CO, which dissociates to form another methyl radical and CO. Finally, two methyl radicals combine to form the stable molecule ethane. 

The HPLC-MS/MS method has been recently applied for the measurement of the cis and trans diastereomers of 5,6-dihydroxy-5,6-dihydrothymidine (8), 5-formyl-2 -deoxyuridine (11) and 5-(hydroxymethyl)-2 -deoxyuridine (10) within cellular DNA exposed to ionizing radiation and heavy particles. The two methyl oxidation products 10 and 11 and thymidine glycols 8 (Chart 3) that are produced within the range of 20 to 100 lesions per 10 normal bases and per Gy (Table 3) are likely to be derived from the decomposition of 5-(hydroperoxymethyl)-2 -deoxyuridine (7) and 5-(6)-hydroperoxy-6-(5)-hydroxy-5,6-dihydrothymidine 5 and 6, respectively. 

Heating chloroacrolein yields 20% of 6-chloro-2-formyl-4//-pyran.l92The formation of pyrans by thermal decomposition of ethyl acetoacetate and its homologs on a copper powder catalyst is patented.193 Surprisingly, 2H-pyran 148 (20%) was reported when 2-oxoglutaric acid reacted with lead(II) nitrate.194... 

Attempts were made to formylate and acetylate (230) but decomposition was extensive and no product could be isolated. Treatment of a solution of (230) in benzene with bromine vapor gave a stable blue cyclazine cation bromide, which was converted on further treatment with bromine into a greenish brown dication dibromide. 

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