Triethylamine with phosgene

Treatment of 2,6-dimethylaniline (121) with phosgene and triethylamine affords the corre-S]ionding isocyanate (122). Condensation of that reactive intermediate with N-isopropylpropyl-cne-1,3-diamine leads to formation of urea 123. This product, recainam (123), acts as membrane Stabilizing agent and thus exhibits both local anesthetic and antiarrhythmic activity [30]. 

The carbonyl chloride reactant was prepared by reacting 2-imidazolidone with methane sulfonyl chloride then that product with phosgene. The mixture was stirred for 10 minutes at 0°C and subsequently further stirred at room temperature until no further addition of triethylamine was necessary to maintain a pH value of 7 to B. 150 parts by volume of water were added and the tetrahydrofuran was largely removed in a rotary evaporator at room temperature. 

To this acid was then added 1 g of 4-ethyl-2,3-dioxo-1-piperazinocarbonyl chloride (from the reaction of N-ethylethylenediamine and diethyl oxalate to give 2,3-dioxo-4-ethyl-piperazine which Is then reacted with phosgene) and the resulting mixture was reacted at 15°C to 20°C for 2 hours. After the reaction, a deposited triethylamine hydrochloride was separated by filtration, and the filtrate was incorporated with 0.4 g of n-butanol to deposit crystals. The deposited crystals were collected by filtration to obtain 1.25 g of white crystals of 6-[ D(—l-Ct-(4-ethyl-2,3-dioxo-1 -piperazinocarbonylaminolphenylacetamido] penicillanic acid. Into a solution of these crystals in 30 ml of tetrahydrofuran was dropped a solution of 0.38 g of a sodium salt of 2-ethyl-hexanoic acid in 10 ml of tetrahydrofuran, upon which white crystals were deposited. The deposited crystals were collected by filtration, sufficiently washed with tetrahydrofuran and then dried to obtain 1.25 g of sodium salt of 6-[D(—)-a-(4-ethyl-2,3-di-0X0-1-piperazinocarbonylaminolphenylacetamido] penicillanic acid, melting point 183°C to 185°C (decomposition), yield 90%. 

Initially, 50 was converted into the benzoxazinone 51 by reaction with phosgene in the presence of triethylamine and 51 was isolated in 95% yield upon crystallization from methanol. Deprotection of the pMB group from 51 was accomplished with ceric ammonium nitrate (CAN) in aqueous acetonitrile. Efavirenz was isolated in 76% yield after crystallization from EtOAc-heptane (5 95), as shown in Scheme 1.19. There were two issues identified in this route. First, lequiv of ani-saldehyde was generated in this reaction, which could not be cleanly rejected from product 1 by simple crystallization to an acceptable level under the ICH guideline. Anisaldehyde was removed from the organic extract as a bisulfite adduct by washing with aqueous Na2S205 twice, prior to the crystallization of 1. Secondly,... 

Nicotinic acid, conversion to anhydride with phosgene and triethylamine, 47,89... 

Tridecanedione, 47, 95 Triethylamine, 46,18 dehydrobromination of a-bromo-y-butyrolactone, 46, 23 dehydrobromination of o.a -dibromo-dibenzyl ketone, 47, 62 dehydrochlorination of cyclohexane-carbonyl chloride, 47, 34 in synthesis of nicotinic anhydride with phosgene, 47, 90 Triethylenetetramine, see Hexamethylenetetramine... 

Chloropropyl)-2-piperidone and 1 -(2-chloroethyl)-2-pyrrolidone were reacted with phosgene in toluene, and the 2-chloro derivatives (466, n = 0, 1, R2 = H, R3 = (CH2), C1, m = 2, 3, R5 = Cl) were then reacted with Meldrum s acid (421) in the presence of triethylamine to give isopropylidene [l-(3-chloroalkyl)piperidin-2-ylidene]malonate and [l-(2-chloroethyl)pyrrolidin-2-ylidene]malonate (468, n = 0, 1 R2 = H ... 

Dimethyl and diethyl (l-methylpyrrolidin-2-ylidene)malonates (e.g., Scheme 38,467, n = 0, R = R1 = Me, Et R2 = H R4 = Me) and diethyl (l-methyl-l,2-dihydroquinolin-2-ylidene)malonate were obtained in 30-52% yields when l-methylpyrrolidin-2-one and 1-methyl-1,2-dihydroquinolin-2-one were first reacted with phosgene and then with dialkyl malonates in the presence of triethylamine in benzene at 60°C (61CB2278 69JA6683). 

Isocyanides Phosgene in combination with triethylamine has generally been preferred to phosphoryl chloride and triethylamine for dehydration of formamides to isocyanides (1, 857). However, use of phosphoryl chloride in combination with diisopropylamine can give isocyanides in yields comparable to those obtained with phosgene. Even so this new method can fail with some simple alkyl formamides. 

Addition of DBU to a solution of 149 in THF induced an elimination reaction accompanied by loss of a molecule of CO2 and provided the unstable amine 150, which was converted in situ into isocyanate 151 by reaction with phosgene and triethylamine. After filtration to remove hydrochloride salts, the solution of 151 was treated with samarium (II) iodide in the presence of lithium chloride. These conditions, which had been previously determined to be optimal for spirooxindole generation on a model system, provided compound 152 as an inseparable 7 1 mixture of diastereoisomers [43]. The major component of this mixture was determined by NOE analysis to have the required configuration, which is consistent with bond formation from the less hindered, convex face of 151 (Scheme 35). 

The diazepine 85 (tetramethyleneurea) has been prepared by a variety of routes. Among these are the treatment of tetramethylene diisocyanate with water,70-72 the rearrangement of the oxime (86) in polyphosphoric acid,73,74 and the reaction of 1,4-diaminobutane with sulfur, methanol, and carbon monoxide at high pressure.75 A novel preparation of 85 involves the reaction of 1,4-diaminobutane with 87 to give the silylated diamine (88). Reaction of 88 with phosgene and triethylamine yielded the bistrimethylsilyldiazepine (89) which was then hydrolyzed in aqueous ethanol to give 85.76... 

Treatment of the amino oxime 156 with phosgene and triethylamine in tetrahydrofuran at — 20°C gives 2-oxo-4,4,5-trimethyl-6-oxa-l,3-diazabi-cyclo[3.1.0]hexane (158) and the oxime 159, presumed to form via the intermediate 7V-oxide 157. ... 

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