Chlorosulfonyl

Chlorosulfonyl isocyanate has been used to introduce 3-carboxamide groups. The initial product, an A -chlorosulfonylcarboxamide, is treated with tri-n-butylstannanc to form the primary carboxamide[15], 3-Cyano groups can also be introduced using chlorosulfonyl isocyanate. The intermediate N-chlorosulfonylindole-3-carboxamide is converted to 3-cyanoindole on reaction with triethylamine[16] or DMF[17],... 

Action of HSO3CI on 2-substituted thiazoles affords the 5-chlorosulfonyl derivatives (337, 338). Addition of 6-phenylthiazolo[2,3-e]tetra2ole to oleum opens the tetrazole ring to form 2-azido-4-phenyI-thiazolyl-5-sulfonic acid, isolated as its salt (339). 5-Chloro-sulphonyl derivative is obtained similarly by action of HSO,Cl. 

Chlorosulfonyl isocyanate is an excellent alternative to alkaline cyanates ia the preparation of hydantoias from stericaHy hindered or labile amino nitriles (62). Imino derivatives similar to (18) can also be obtained by addition of sonitnles to imines followed by treatment with a cyanate (63). 

Fig. 7. Synthesis of monocarbams where P is an amino protecting group and CSI is chlorosulfonyl isocyanate. TFA is trifluoroacetic acid...

The ring-chlorinated derivatives of toluene form a group of stable, industrially important compounds. Many chlorotoluene isomers can be prepared by direct chlorination. Other chlorotoluenes are prepared by indirect routes involving the replacement of amino, hydroxyl, chlorosulfonyl, and nitro groups by chlorine and the use of substituents, such as nitro, amino, and sulfonic acid, to orient substitution followed by their removal from the ring. 

Chlorosulfonation of benzotrichloride with chlorosulfonic acid (28) or with sulfur trioxide (29) gives y -chlorosulfonyl benzoyl chloride [4052-92-0] in high yield. Nitration with nitronium fluoroborate in sulfolane gives 68% y -nitro-benzotrichloride [709-58-0] along with 13% of the ortho and 19% of the para isomers (30). 

In cases where a large excess of acid is undesirable, chlorosulfonic acid is employed. An excess of chlorosulfonic acid leads to the introduction of a chlorosulfonyl group which is a useful synthon for the preparation of sulfonamides and sulfonate esters. 

The Af-chlorosulfonyl-4-alkenyl-/3-lactams (119), formed by cycloaddition of CSI with the corresponding dienes, undergo a thermal rearrangement to give the formal [4 + 2]... 

AT-Unsubstituted azetidin-2-ones are versatile intermediates in the preparation of a variety of novel /3-lactam containing systems. They are usually made either by reductive dechlorosulfonylation of alkene/chlorosulfonyl isocyanate cycloadducts cf. Section 5.09.3.3.2), which... 

Woodward s synthesis, 4, 416-419 Chlorophyll b, 4, 382 Chlorophyll c, 4, 382 Chlorophyll d, 4, 382 Chlorophylls, 4, 378 biosynthesis reviews, 1, 99 structure, 4, 370 substituents reactions, 4, 402 Chloroporphyrin e, 4, 404 Chloroprothixene pharmacology, 3, 942 Chloropyramine as antihistamine, 1, 177 Chloropyrifos synthesis, 2, 201 Chloropyrifos-ethyl as insecticide, 2, 516 Chloropyrifos-methyl as insecticide, 2, 516 Chloroquine, 1, 145 adsorption on nucleic acids, 1, 179 as antimalarial, 1, 173, 2, 517 Chloroquine, hydroxy-as antimalarial, 2, 517 Chlorosulfonyl isocyanate cycloaddition reactions... 

Addition, chloroform, to olefins to form 1,1,3 tnchloroalkanes, 46, 106 chlorosulfonyl isocyanate to isobutylene to give 0-isovaleiolactam-N-sulfonyl chloride, 46, SI cyclohexyl amine to silicon tetraiso-cyanate, 46, 69... 

In contrast, addition of dimethyl acetylenedicarboxylate to cyclopent[6]azepine (6) is slow and furnishes, in 53% yield, a mixture of the dimeric 1 2 adduct 7 (red crystals), the 1 3 adduct 8 (yellow oil), and an unidentified purple oil.2 Surprisingly, cyclopent[6]azcpine fails to react with other common dienophiles such as ethenetetracarbonitrile, diethyl maleate and chlorosulfonyl isocyanate. 

Substituted azocine systems are much more stable than the parent compound, and 2-methoxy derivatives have been intensively examined. Starting from cyclohexa-1,4-diene (3), a [2 + 2] cycloaddition with chlorosulfonyl isocyanate, followed by removal of the chlorosulfonyl group, leads to the /3-lactam 4, which can be transformed by O-methylation with Meerwein s salt into the corresponding imidate. Monobromination with A-bromosuccinimide and subsequent treatment with base results in a methoxyazabicyclo[4.2.0]octatriene derivative, which spontaneously isomerizes to 2-methoxyazocine (5).13,14... 

Method B A mixture of copper(II) phthalocyanine (3 1.2 g, 2 mmol) and C1S03H (5 mL) was stirred for 3 h at 138-140 C and then for 3 h with SOCI, (1.5 mL) at 80 85 C. The mixture was then cooled, poured onto ice, and filtered. The precipitate was washed on the filter with cold H,0 until neutral, pressed off well, and dried. The l,4-tetra(chlorosulfonyl)phthalocyanine 4 obtained was mixed with Et2NH (2mL) in CHCl3 (50 mL)and the mixture was stirred for 24 hat 25 30 C. By repeated chromatographic separation (alumina, CHC13/ benzene 2 1) the title compound 5 was isolated yield 0.3 g (13 %). 

Heterocyclization of chlorosulfonyl isocyanate with ethyl-3-oxo-2-(arylhydrazono)butanoates 1011 (2 1) gave thiadiazolotriazinediones 1012 (91H1517) (Scheme 188). 

Caution Chlorosulfonyl isocyanate, is highly corrosive. This preparation should be carried out in an efficient hood, and rubber gloves should be worn during the first step. 

A. Methyl (Chlorosulfonyl)carbarriate [Carbamic acid, (chlorosulfonyl)-, methyl ester], A dry, two-necked, 500-ml., round-bottomed flask is... 

The preparation of chlorosulfonyl isocyanate is described in Org. Syn., Coll. Vol. 5, 226 (1973). This compound is highly corrosive, reacts explosively with water, and may be contaminated with cyanogen chloride. 

The water bath should not be positioned around the flask until after the solution of chlorosulfonyl isocyanate has been added. 

Calcium hydride (CaH,) [7789-78-8], 12 Carbamic acid, (chlorosulfonyl)-, methyl ester [36914-92-8], 40 CARBAMIC ACID, HEXYL-, METHYL ESTER [22139-32-8],40 Carbamic acid, [2-oxo-2-[(phenylmethyl)-amino] ethyl], phenylmethyl ester [2642-32-2], 93... 

L//-Indole, 3<2-phenyl-l, 3-dithian-2-yl), 10 Indoles, 34 Indoles, 3-acyl-, 8 Indoles, 3 -alkyl, 8 Isocyanate, chlorosulfonyl [Sulfuryl chlonde isocyanate], 41 Isocyanate,2-propyl- [Propane, 2-iso-cyanato-], 96... 

The reactive compound chlorosulfonyl isocyanate (ClSOaNCO, forms P-lactams even with unactivated alkenes, as well as with imines, allenes, conjugated dienes, and cyclopropenes. With microwave irradiation, alkyl isocyanates also... 

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