Pilat, S. published the artcileFormation of cyclopentylalkanesulfonates, Product Details of C7H13Br, the publication is Berichte der Deutschen Chemischen Gesellschaft [Abteilung] B: Abhandlungen (1939), 1527-31, database is CAplus.
The Na naphthenesulfonates obtained from natural naphthenic acids through the naphthenyl alcs. and chlorides (C. A. 32, 8753.5) are characterized by their excellent foaming and wetting properties in aqueous solution For comparison with these substances, whose structure has not been fully cleared up, P. and T. undertook the preparation of some cyclic sulfonates (chiefly cyclopentane derivatives, since the naphthenic acids in petroleums are for the most part derived from cyclopentane) in which the sulfonic acid is in primary combination, i. e., as CH2SO3H. The starting point for the preparation of sulfonates with a straight alkyl chain, C5H9(CH2)nSO3Na (n = 2, 4 or 7) was cyclopentanol, which was converted with boiling concentrated HCl and CaCl2 into the chloride (87% yield); this through the Grignard reagent with HCHO gave the carbinol, C5H9CH2OH, which, in turn, was converted into the chloride. 2-Cyclopentylethanol (I) and 4-cyclopentylbutanol (II), as also 2-menthylethanol (III), were prepared by the Grignard method for introducing CH2.CH2 chains: RMgBr + CH2.CH2.O → RCH2CH2OMgBr. Chains of 3 CH2 groups were introduced by treating Grignard compounds with p-MeC6H4SO3(CH2)3Cl (IV) or with trimethylene oxide; in this way (7-chloroheptyl)cyclopentane (V) was prepared from C5H9(CH2)4Br and II from C5H9CH2Cl. For the preparation of sulfonates with a branched chain fenchone was used, which was converted by KOH at 240° into fencholic acid (VI). Reduction of the Et ester of VI gave fencholyl alc. (VII), converted with PCl5 into the chloride, which with Na2SO3 gave 50% Na fencholylsulfonate and, through fencholylmalonic acid, yielded fencholylacetic acid (VIII). Reduction of the Et ester of VIII, conversion of the 2-fencholylethanol (IX) into the chloride and subsequent Strecker reaction yielded Na fencholylethanesulfonate (50% yield), very hygroscopic. Investigation of aqueous solutions of the Na salts so obtained, which will be described in detail later, showed, among other things, that sulfonates in which a cyclopentane ring carries small alkyl groups are characterized by an especially high degree of surface activity and in this respect surpass both cyclopentanes with a long side chain and alkylated cyclohexanes. I, b11 85°, was obtained in 45% yield by a modification of the Yohe and Adams method (C. A. 22, 2148). Chloride (71% from I and 1.1 mols. PCl5 refluxed 2 h. in petr. ether), b60 85-6°, d420 0.955, nD20 1.4527; 26.5 g. heated 8 h. at 200° with 80 g. crystallized Na2SO3 in an autoclave, with stirring, gave 39 g. (97.5%) Na 2-cyclopentylethanesulfonate, silvery non-hygroscopic needles. (2-Bromoethyl)cyclopentane (71.2% from I heated 2.5 h. with HBr-concentrated H2SO4), b19 77°, d420 1.290, nD20 1.4865; its Grignard reagent with ethylene oxide gave 68% II, b2 87-92°, nD20 1.4610, d420 0.903 (from C5H9CH2Cl and trimethylene oxide the yield was only 5%). (4-Bromobutyl)cyclopentane (90% from II with HBr-H2SO4), b17 110-11°, nD20 1.4820, d420 1.187, gives with Na2SO3 after 8 h. at 160° in a rotating autoclave Na 4-cyclopentylbutanesulfonate. V (10% from C5H9(CH2)4Br and IV), b. 120-5°; Na 7-cyclopentylheptanesulfonate, strongly hygroscopic. Menthyl bromide (80% from menthol and HBr-H2SO4), b13 105.5°, d420 1.162, nD20 1.4852. III (20%), b10 132-6°; chloride (35%), b10 120-5°; Na 2-menthylethanesulfonate. VII (84.5%), b10 96.5°, [α]D 8.6°; chloride, b9 84°, d421.5 0.949, nD17 1.4702. VIII (46%), b10 165-6°; Et ester, b10 146-8°. IX (5% from the Grignard compound of fencholyl chloride with ethylene oxide, or 76% by reduction of the Et ester of VIII with Na in absolute alc.), b10 134-5°, nD18 1.4761; chloride (65%), b10 120-6°.
Berichte der Deutschen Chemischen Gesellschaft [Abteilung] B: Abhandlungen published new progress about 18928-94-4. 18928-94-4 belongs to bromides-buliding-blocks, auxiliary class Bromide,Aliphatic cyclic hydrocarbon, name is (2-Bromoethyl)cyclopentane, and the molecular formula is C7H13Br, Product Details of C7H13Br.
Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary